BRAIN
AND
LANGUAGE
‘t&583-596
(1992)
Allocation of Attention, Reading Skills, and Deafness ILA PARASNIS National Technical Institute for the Deaf, Rochester Institute of Technology Brannan and Williams (1987) found that poor readers cannot successfully utilize parafoveal cues to identify letter targets. Whether a similar deficit in the use of cue information occurs in deaf poor readers and whether it is only specific to processes that capture attention automatically were investigated in congenitally deaf young adults classified as poor or good readers and hearing controls classified as good readers. Subjects were presented with central or parafoveal cues that varied in cue validity probability, followed by letter targets presented to the left or right of fixation. The reaction time data analyses showed significant main effects for cue type and cue location and significant interactions among cue type, cue location, cue validity probability, and visual field. No significant main effect or interactions involving groups were found. These results raise the possibility that reading difficulties associated with deafness do not involve a deficit in the visual attentional system of deaf people. They also confirm that parafoveal cues are more effective than central cues in capturing attention. Q 1992 Academic Press, h.
Posner and his co-workers (Posner, 1980; Posner, Nissen, & Ogden, 1978) have shown in stimulus detection tasks that attention can be directed to different parts of the visual field away from ocular fixation by using prior cues that are presented either centrally or peripherally. Stimulus detection efficiency is increased in cued locations and decreased in noncued locations. Using Posner’s paradigm, Brannan and Williams (1987) found that children who were poor readers did not effectively use parafovea1 cues that predicted target location in responding to those targets. However, children who were good readers and adult good readers successfully used parafoveal cues. Brannan and Williams suggested that proficiency in manipulating attentional resources may be related to good This research of Education. I correspondence search, National Lomb Memorial
was conducted during the course of an agreement with the U.S. Department thank Vincent J. Samar for his critical reading of the manuscript. Address and reprint requests to Ila Parasnis, Department of Communication ReTechnical Institute for the Deaf, Rochester Institute of Technology, One Drive, P.O. Box 9887, Rochester, NY 14623-0887. 583 0093-934x192 $5.00 Copyright 0 1992 by Academic Press, Inc. All rights of reproduction in any form reserved.
584
ILA PARASNIS
reading skills, and poor readers may have some kind of attentional deficit in processing peripheral information. On average, deaf people have significantly lower reading skills than normal-hearing people. In one study of reading achievement of deaf people, approximately half of the deaf high school population was found to read below a fourth-grade level (Di Francesca, 1972). Early language deprivation, difficulties with English syntax, and inadequate phonological coding processes are some of the recognized factors that contribute to poor reading skills in the deaf population (see Conrad, 1979; King & Quigley, 1985; Quigley & Paul, 1984). However, there is also some evidence from studies using a variety of tasks that the perceptual and attentional processes of deaf people sometimes differ from those of hearing people (Neville & Lawson, 1987; Neville, Schmidt, & Kutas, 1983; Parasnis, 1983; Parasnis & Samar, 1985). Therefore, it is possible that the differences between deaf and hearing people in their reading skills may be partly determined by the adequacy of the functioning of their attentional system. The present study examined the relationship between visual attentional processes and reading skills in deaf and hearing young adults to search for evidence that poor reading skills in deaf people might involve a specific deficit in the attentional system of those readers. The finding of Brannan and Williams was that the effective use of cues was associated with good reading skills. The purpose of this study was to see if this particular attentional process is a correlate of good reading skills in deaf people and acts as a diagnostic tool to separate good from poor readers.’ The present study was generally patterned after the Brannan and Williams study. It also extended the Brannan and Williams paradigm by using fovea1 in addition to parafoveal cues to direct attention to the parafoveal targets. The purpose of this extension was to investigate whether an observed deficit in the use of cue information by deaf poor readers is specific to the processing of peripheral information or is more general in nature. Posner (1980) has proposed that allocation of attentional resources is controlled either by an endogenous, volitional orienting in response to a symbolic indicator such as a fovea1 cue or by an exogenous, nonvolitional orienting to a source of extrafoveal stimulation such as a peripheral cue ’ It should be made clear here that the task used in this study or by Brannan and Williams may not tap the actual visual attentional processes involved in the reading process. Thus, the relationship between the visual attentional processes tested in this study and reading skills is expected to exist under the assumption that the same attentional system involved in the reading process is also functioning to control attention in the reaction time (RT) task used in this study. Presumably, the actual details of attentional regulation that the system puts into play are task specific and task appropriate. The system may be configured differently for reading and for RT tasks, in response to the differing task demands. Nevertheless, a deficit at the level of the attentional system might well be manifested by performance deficits in both kinds of tasks; hence the hypothetical correlation under examination.
VISUAL
ATTENTION
AND DEAFNESS
585
in a parafoveal location. Jonides (1981) directly compared the effects of peripheral and central cues and found that attention is more efficiently directed by a peripheral flash at the target location than by a central cue pointing to that location. Whether a single attentional mechanism is activated by the peripheral and central cues (Jonides & Yantis, 1988; Yantis & Jonides, 1984) or whether separate attentional systems are activated as Briand and Klein (1987) have suggested has not yet been definitively determined. However, the available research clearly demonstrates that peripheral and central cues play different roles in directing attention (e.g., Jonides, 1981; Yantis & Jonides, 1984). Finally, the present study was designed to correct a methodological difficulty with the Brannan and Williams study. Brannan and Williams reported an overall right field advantage for adult and young good readers. However, they did not report in their paper what response mode was used to collect the accuracy data (i.e., simple key press, vocal response, etc.). Therefore, it is not clear whether this right field advantage is simply an artifact of their design or signals a true left hemisphere advantage in performing the letter identification task. A bimanual response mode was used in the present study to determine whether the overall right field advantage for adult and young good readers reported by Brannan and Williams can be obtained under better controlled conditions. METHOD Subjects Twelve normal-hearing college students from the Rochester Institute of Technology (RIT), Rochester, New York, and 24 deaf college students from the National Technical Institute for the Deaf (NTID), one of the colleges of RIT, served as subjects and were paid for their help. Subjects ranged in age from 18 to 30 years. All except 2 deaf students were right-handed. There were 6 males and 6 females in each of the hearing and deaf groups of good readers and there were 5 males and 7 females in the deaf group of poor readers. All students had normal or corrected vision as assessed by ophthalmological screening procedures routinely employed at NTID for deaf students and by self reports from hearing students. All students reported that they had no history of neurological disorders. Subjects were selected on the basis of their scores (expressed in grade equivalents) on the California Reading Comprehension Test (Tiegs & Clark, 1963) given before the experiment. The test scores showed that all hearing students read at or around the 12th grade level. Twelve of the deaf students read at the 10th grade level or above (good readers), and 12 read at or around the 8th grade level (poor readers). It should be noted that the category labels good and poor readers are used only as relative terms to identify the groups and they have no calibrated meaning outside the context of this study. The mean score of the deaf good readers on the California Reading Comprehension Test (Tiegs & Clark, 1963) was 11.1 (SD = .6), and 8.4 (SD = .4) for the deaf poor readers. The mean score of hearing readers was 11.8 (SD = .3). All deaf subjects had a severe or profound hearing loss with onset of deafness at birth. All deaf subjects had pure tone average hearing loss (PTA) in the better ear at 500-lOOt2000 Hz (ANSI, 1969) of more than 80 dB HL. Furthermore, all deaf subjects had an auditory discrimination profile rating of 3 or below, which means that these subjects were at best able to recognize only 50% of the Spondee test words and scored less than 50% on
586
ILA PARASNIS
the CID Everyday Sentence Lists (see Johnson, 1975, for further information). Ah deaf subjects except two were rated 4 or 5 on a 5-point rating scale used at NTID to assess sign language skill (see Caccamise & Cagle, 1989, for a description of the test). These scores indicate that they were highly skilled, fluent signers. The two remaining subjects were rated 1, indicating that they possessed no or minimal sign language skill. One of these subjects was in the deaf good readers’ group and the other in the deaf poor readers’ group. Group t tests showed that the two deaf groups did not differ significantly in the mean PTA (1 < 1). The mean pure tone average hearing loss was 94.8 dB HL (SD = 7.7 dB HL) for the deaf good readers and 93.2 dB HL (SD = 7.8 dB HL) for the deaf poor readers. One-way analysis of variance of the data showed that the groups did not differ significantly in their age (F(2, 33) = 1.5; p > .lO). The mean age in years was 21.1 for hearing readers (SD = 4.0) 20.7 for deaf good readers (SD = 1.4), and 22.6 for deaf poor readers (SD = 2.4). Stimuli and apparatus. The stimuli were white characters on a black background. They were presented on a CRT by an IBM PC microcomputer. On each trial, a fixation stimulus appeared followed by a cue and then a target stimulus. The fixation stimulus was an elongated asterisk sign that was 1” high and .5” wide and always appeared in the center. The target stimuli consisted of the letters S or N, which were 1” high and .5” wide and appeared either to the left or to the right, 9” away from the center of fixation. In one condition (the Central Cue Condition), the cue preceding the target appeared in the center and consisted of a 1.4”-long arrow pointing to the left or to the right. In another condition (the Peripheral Cue Condition), it appeared in the parafoveal location and consisted of a V-long vertical line appearing directly above the position of the target stimulus. Experimental design andprocedure. Each subject was tested in both conditions: the Central Cue Condition and the Peripheral Cue Condition. Within each condition, there were two blocks of trials. In one block, the probability that the cue would accurately predict the target position was 50%. In the other, it was 80%. In both conditions the trial structure was as follows. The word “READY” initially appeared on the screen to signal the subject to initiate the trial. The subject did so by pressing two keys simultaneously, one with each thumb. The fixation stimulus was then presented for 500 msec followed by a central or a parafoveal cue presented for 30 msec. After a 50-msec blank interval, the target stimulus (S or N) appeared for 30 msec. The subject then gave a simultaneous bimanual response to indicate whether an S or an N was presented. Half of the subjects in each of the three groups responded simultaneously with their index fingers to indicate S and their middle fingers to indicate N, while the other half used their index fingers to indicate N and their middle fingers to indicate S. Reaction time was measured from the onset of the target stimulus. A maximum time of 1300 msec was allowed for the response. The accuracy of the response was also recorded. Subjects were given immediate feedback on each trial regarding the accuracy of their response by the centrally presented words “RIGHT,” “WRONG,” or “TIME OUT” (in the case of a response longer than 1330 msec). After that, the “READY” signal again appeared on the screen for the next trial. Eighty trials were given in each probability block. The target alternatives S and N appeared equally often and the target was presented to the left or right of fixation equally often. The arrows in the center pointed to the left or right equally often and the vertical lines used as parafoveal cues occurred equally often to the left or right. On valid trials the target appeared in the position predicted by the cue and on invalid trials it appeared in the position opposite to the one predicted by the cue. The order of blocks within each condition was counterbalanced and the order of conditions was also counterbalanced across subjects within each group. Furthermore, each deaf subject had a matched hearing control who received the same trial blocks in the same order and within each group another subject who received the same blocks in a counterbalanced order. The order of trials within blocks was pseu-
VISUAL
ATTENTION
AND DEAFNESS
587
dorandom such that no trial type appeared more than four times in a row. In total, each subject responded to 320 trials in four blocks. Each condition was preceded by two practice runs of 16 trials each. The first practice run used an interstimulus interval (ISI) of 150 msec for subjects to get used to the task, and the second practice run used an IS1 of 50 msec. These practice runs were helpful in determining whether the subjects understood the instructions and could perform the task. Each subject was run individually in a l-hr session. Each subject was seated with his or her chin rested on a chin rest which was positioned 14.5 in. from the center of the CRT screen. The subjects were instructed to look at the center where the fixation stimulus appeared and were told not to move their eyes during a trial. They were also told to use the cues to prepare to respond to the target stimuli and were informed about the probability of cue validity. They were told to respond as quickly as possible but to keep their error rates low. The instructions were signed and spoken for deaf students and were identical in content to those given orally to hearing students.
RESULTS AND DISCUSSION
The average error rate was low (6.2%, deaf good readers; 7%, deaf poor readers; 4.2%, hearing readers). Nevertheless, the accuracy data were analyzed to examine whether the groups differed in their performance and whether any speed-accuracy tradeoffs existed that might influence the interpretation of the reaction time (RT) data. The percentages of correct data were subjected to arcsine transformation before this analysis. Analyses of variance using a multivariate approach to repeated measures were then conducted on these data. Group was a between-subjects factor (Deaf Good Readers, Deaf Poor Readers, Hearing Good Readers) and Cue Location (Peripheral Cue Condition, Central Cue Condition), Probability Block (50%, 80%), Visual Field (Left, Right), and Cue Type (Valid, Invalid) were within-subjects factors. The main effect for Cue Type was significant (F(1, 33) = 4.06; p
AND
LANGUAGE
‘t&583-596
(1992)
Allocation of Attention, Reading Skills, and Deafness ILA PARASNIS National Technical Institute for the Deaf, Rochester Institute of Technology Brannan and Williams (1987) found that poor readers cannot successfully utilize parafoveal cues to identify letter targets. Whether a similar deficit in the use of cue information occurs in deaf poor readers and whether it is only specific to processes that capture attention automatically were investigated in congenitally deaf young adults classified as poor or good readers and hearing controls classified as good readers. Subjects were presented with central or parafoveal cues that varied in cue validity probability, followed by letter targets presented to the left or right of fixation. The reaction time data analyses showed significant main effects for cue type and cue location and significant interactions among cue type, cue location, cue validity probability, and visual field. No significant main effect or interactions involving groups were found. These results raise the possibility that reading difficulties associated with deafness do not involve a deficit in the visual attentional system of deaf people. They also confirm that parafoveal cues are more effective than central cues in capturing attention. Q 1992 Academic Press, h.
Posner and his co-workers (Posner, 1980; Posner, Nissen, & Ogden, 1978) have shown in stimulus detection tasks that attention can be directed to different parts of the visual field away from ocular fixation by using prior cues that are presented either centrally or peripherally. Stimulus detection efficiency is increased in cued locations and decreased in noncued locations. Using Posner’s paradigm, Brannan and Williams (1987) found that children who were poor readers did not effectively use parafovea1 cues that predicted target location in responding to those targets. However, children who were good readers and adult good readers successfully used parafoveal cues. Brannan and Williams suggested that proficiency in manipulating attentional resources may be related to good This research of Education. I correspondence search, National Lomb Memorial
was conducted during the course of an agreement with the U.S. Department thank Vincent J. Samar for his critical reading of the manuscript. Address and reprint requests to Ila Parasnis, Department of Communication ReTechnical Institute for the Deaf, Rochester Institute of Technology, One Drive, P.O. Box 9887, Rochester, NY 14623-0887. 583 0093-934x192 $5.00 Copyright 0 1992 by Academic Press, Inc. All rights of reproduction in any form reserved.
584
ILA PARASNIS
reading skills, and poor readers may have some kind of attentional deficit in processing peripheral information. On average, deaf people have significantly lower reading skills than normal-hearing people. In one study of reading achievement of deaf people, approximately half of the deaf high school population was found to read below a fourth-grade level (Di Francesca, 1972). Early language deprivation, difficulties with English syntax, and inadequate phonological coding processes are some of the recognized factors that contribute to poor reading skills in the deaf population (see Conrad, 1979; King & Quigley, 1985; Quigley & Paul, 1984). However, there is also some evidence from studies using a variety of tasks that the perceptual and attentional processes of deaf people sometimes differ from those of hearing people (Neville & Lawson, 1987; Neville, Schmidt, & Kutas, 1983; Parasnis, 1983; Parasnis & Samar, 1985). Therefore, it is possible that the differences between deaf and hearing people in their reading skills may be partly determined by the adequacy of the functioning of their attentional system. The present study examined the relationship between visual attentional processes and reading skills in deaf and hearing young adults to search for evidence that poor reading skills in deaf people might involve a specific deficit in the attentional system of those readers. The finding of Brannan and Williams was that the effective use of cues was associated with good reading skills. The purpose of this study was to see if this particular attentional process is a correlate of good reading skills in deaf people and acts as a diagnostic tool to separate good from poor readers.’ The present study was generally patterned after the Brannan and Williams study. It also extended the Brannan and Williams paradigm by using fovea1 in addition to parafoveal cues to direct attention to the parafoveal targets. The purpose of this extension was to investigate whether an observed deficit in the use of cue information by deaf poor readers is specific to the processing of peripheral information or is more general in nature. Posner (1980) has proposed that allocation of attentional resources is controlled either by an endogenous, volitional orienting in response to a symbolic indicator such as a fovea1 cue or by an exogenous, nonvolitional orienting to a source of extrafoveal stimulation such as a peripheral cue ’ It should be made clear here that the task used in this study or by Brannan and Williams may not tap the actual visual attentional processes involved in the reading process. Thus, the relationship between the visual attentional processes tested in this study and reading skills is expected to exist under the assumption that the same attentional system involved in the reading process is also functioning to control attention in the reaction time (RT) task used in this study. Presumably, the actual details of attentional regulation that the system puts into play are task specific and task appropriate. The system may be configured differently for reading and for RT tasks, in response to the differing task demands. Nevertheless, a deficit at the level of the attentional system might well be manifested by performance deficits in both kinds of tasks; hence the hypothetical correlation under examination.
VISUAL
ATTENTION
AND DEAFNESS
585
in a parafoveal location. Jonides (1981) directly compared the effects of peripheral and central cues and found that attention is more efficiently directed by a peripheral flash at the target location than by a central cue pointing to that location. Whether a single attentional mechanism is activated by the peripheral and central cues (Jonides & Yantis, 1988; Yantis & Jonides, 1984) or whether separate attentional systems are activated as Briand and Klein (1987) have suggested has not yet been definitively determined. However, the available research clearly demonstrates that peripheral and central cues play different roles in directing attention (e.g., Jonides, 1981; Yantis & Jonides, 1984). Finally, the present study was designed to correct a methodological difficulty with the Brannan and Williams study. Brannan and Williams reported an overall right field advantage for adult and young good readers. However, they did not report in their paper what response mode was used to collect the accuracy data (i.e., simple key press, vocal response, etc.). Therefore, it is not clear whether this right field advantage is simply an artifact of their design or signals a true left hemisphere advantage in performing the letter identification task. A bimanual response mode was used in the present study to determine whether the overall right field advantage for adult and young good readers reported by Brannan and Williams can be obtained under better controlled conditions. METHOD Subjects Twelve normal-hearing college students from the Rochester Institute of Technology (RIT), Rochester, New York, and 24 deaf college students from the National Technical Institute for the Deaf (NTID), one of the colleges of RIT, served as subjects and were paid for their help. Subjects ranged in age from 18 to 30 years. All except 2 deaf students were right-handed. There were 6 males and 6 females in each of the hearing and deaf groups of good readers and there were 5 males and 7 females in the deaf group of poor readers. All students had normal or corrected vision as assessed by ophthalmological screening procedures routinely employed at NTID for deaf students and by self reports from hearing students. All students reported that they had no history of neurological disorders. Subjects were selected on the basis of their scores (expressed in grade equivalents) on the California Reading Comprehension Test (Tiegs & Clark, 1963) given before the experiment. The test scores showed that all hearing students read at or around the 12th grade level. Twelve of the deaf students read at the 10th grade level or above (good readers), and 12 read at or around the 8th grade level (poor readers). It should be noted that the category labels good and poor readers are used only as relative terms to identify the groups and they have no calibrated meaning outside the context of this study. The mean score of the deaf good readers on the California Reading Comprehension Test (Tiegs & Clark, 1963) was 11.1 (SD = .6), and 8.4 (SD = .4) for the deaf poor readers. The mean score of hearing readers was 11.8 (SD = .3). All deaf subjects had a severe or profound hearing loss with onset of deafness at birth. All deaf subjects had pure tone average hearing loss (PTA) in the better ear at 500-lOOt2000 Hz (ANSI, 1969) of more than 80 dB HL. Furthermore, all deaf subjects had an auditory discrimination profile rating of 3 or below, which means that these subjects were at best able to recognize only 50% of the Spondee test words and scored less than 50% on
586
ILA PARASNIS
the CID Everyday Sentence Lists (see Johnson, 1975, for further information). Ah deaf subjects except two were rated 4 or 5 on a 5-point rating scale used at NTID to assess sign language skill (see Caccamise & Cagle, 1989, for a description of the test). These scores indicate that they were highly skilled, fluent signers. The two remaining subjects were rated 1, indicating that they possessed no or minimal sign language skill. One of these subjects was in the deaf good readers’ group and the other in the deaf poor readers’ group. Group t tests showed that the two deaf groups did not differ significantly in the mean PTA (1 < 1). The mean pure tone average hearing loss was 94.8 dB HL (SD = 7.7 dB HL) for the deaf good readers and 93.2 dB HL (SD = 7.8 dB HL) for the deaf poor readers. One-way analysis of variance of the data showed that the groups did not differ significantly in their age (F(2, 33) = 1.5; p > .lO). The mean age in years was 21.1 for hearing readers (SD = 4.0) 20.7 for deaf good readers (SD = 1.4), and 22.6 for deaf poor readers (SD = 2.4). Stimuli and apparatus. The stimuli were white characters on a black background. They were presented on a CRT by an IBM PC microcomputer. On each trial, a fixation stimulus appeared followed by a cue and then a target stimulus. The fixation stimulus was an elongated asterisk sign that was 1” high and .5” wide and always appeared in the center. The target stimuli consisted of the letters S or N, which were 1” high and .5” wide and appeared either to the left or to the right, 9” away from the center of fixation. In one condition (the Central Cue Condition), the cue preceding the target appeared in the center and consisted of a 1.4”-long arrow pointing to the left or to the right. In another condition (the Peripheral Cue Condition), it appeared in the parafoveal location and consisted of a V-long vertical line appearing directly above the position of the target stimulus. Experimental design andprocedure. Each subject was tested in both conditions: the Central Cue Condition and the Peripheral Cue Condition. Within each condition, there were two blocks of trials. In one block, the probability that the cue would accurately predict the target position was 50%. In the other, it was 80%. In both conditions the trial structure was as follows. The word “READY” initially appeared on the screen to signal the subject to initiate the trial. The subject did so by pressing two keys simultaneously, one with each thumb. The fixation stimulus was then presented for 500 msec followed by a central or a parafoveal cue presented for 30 msec. After a 50-msec blank interval, the target stimulus (S or N) appeared for 30 msec. The subject then gave a simultaneous bimanual response to indicate whether an S or an N was presented. Half of the subjects in each of the three groups responded simultaneously with their index fingers to indicate S and their middle fingers to indicate N, while the other half used their index fingers to indicate N and their middle fingers to indicate S. Reaction time was measured from the onset of the target stimulus. A maximum time of 1300 msec was allowed for the response. The accuracy of the response was also recorded. Subjects were given immediate feedback on each trial regarding the accuracy of their response by the centrally presented words “RIGHT,” “WRONG,” or “TIME OUT” (in the case of a response longer than 1330 msec). After that, the “READY” signal again appeared on the screen for the next trial. Eighty trials were given in each probability block. The target alternatives S and N appeared equally often and the target was presented to the left or right of fixation equally often. The arrows in the center pointed to the left or right equally often and the vertical lines used as parafoveal cues occurred equally often to the left or right. On valid trials the target appeared in the position predicted by the cue and on invalid trials it appeared in the position opposite to the one predicted by the cue. The order of blocks within each condition was counterbalanced and the order of conditions was also counterbalanced across subjects within each group. Furthermore, each deaf subject had a matched hearing control who received the same trial blocks in the same order and within each group another subject who received the same blocks in a counterbalanced order. The order of trials within blocks was pseu-
VISUAL
ATTENTION
AND DEAFNESS
587
dorandom such that no trial type appeared more than four times in a row. In total, each subject responded to 320 trials in four blocks. Each condition was preceded by two practice runs of 16 trials each. The first practice run used an interstimulus interval (ISI) of 150 msec for subjects to get used to the task, and the second practice run used an IS1 of 50 msec. These practice runs were helpful in determining whether the subjects understood the instructions and could perform the task. Each subject was run individually in a l-hr session. Each subject was seated with his or her chin rested on a chin rest which was positioned 14.5 in. from the center of the CRT screen. The subjects were instructed to look at the center where the fixation stimulus appeared and were told not to move their eyes during a trial. They were also told to use the cues to prepare to respond to the target stimuli and were informed about the probability of cue validity. They were told to respond as quickly as possible but to keep their error rates low. The instructions were signed and spoken for deaf students and were identical in content to those given orally to hearing students.
RESULTS AND DISCUSSION
The average error rate was low (6.2%, deaf good readers; 7%, deaf poor readers; 4.2%, hearing readers). Nevertheless, the accuracy data were analyzed to examine whether the groups differed in their performance and whether any speed-accuracy tradeoffs existed that might influence the interpretation of the reaction time (RT) data. The percentages of correct data were subjected to arcsine transformation before this analysis. Analyses of variance using a multivariate approach to repeated measures were then conducted on these data. Group was a between-subjects factor (Deaf Good Readers, Deaf Poor Readers, Hearing Good Readers) and Cue Location (Peripheral Cue Condition, Central Cue Condition), Probability Block (50%, 80%), Visual Field (Left, Right), and Cue Type (Valid, Invalid) were within-subjects factors. The main effect for Cue Type was significant (F(1, 33) = 4.06; p
