Verbal and visual instruction with mental retardation: The role of subject characteristics and task factors

Past research and theory presents an inconsistent picture concerning the relative value of verbal versus visual instructional programs for individuals with mental retardation. From an empirical perspective, there is evidence that this inconsistency may be due to the differences in the type of tasks and the specific abilities of the subjects employed across studies. In this research, the effects of three instructional procedures (verbal, visual, and verbal plus visual) were evaluated with mentally retarded persons who varied in verbal and visual ability. Performance was examined on a visual task which incorporated stimuli of varying degrees of familiarity to the subjects. The results indicated that the use of the combined verbal-visual instruction procedure was more effective than the other two training programs when task stimuli were familiar to the subjects. When task stimuli were unfamiliar, instructional procedures which had a visual component were found to be superior to a procedure which employed only the use of verbal component. The subjects' visual ability was most strongly associated with performance outcome when visual instruction was employed and unfamiliar task stimuli were sorted. In contrast, subjects' verbal ability appeared to be equally important across instructional and task conditions. The implications of the results for the design of instructional programs and for future research are discussed.     

A tachistoscopic study of hemispheric processing in stuttering and nonstuttering children

Hemispheric processing, expressed as mean reaction time to various visual stimuli presented to the left and right visual fields, was investigated in eighteen stuttering and nonstuttering children. Tachistoscopic procedures were used to present linguistic stimuli (words and nonwords) as well as nonlinguistic stimuli (familiar and unfamiliar geometric figures) to the visual fields. Subjects responded by pressing a telegraph key when they perceived a real word or a familiar geometric figure. They were to make no response when they perceived nonwords or unfamiliar geometric figures. Faster reaction times were taken as an index of the most efficient or dominant hemisphere for a given task. No significant differences were found in mean reaction times for groups, visual fields, type of task, nor any of their interactions. Likewise, the data on accuracy also did not suggest that a larger proportion of stutters responded more accurately when linguistic stimuli were presented to the right hemisphere. Based on mean reaction times and on accuracy data, the stuttering and nonstuttering children performed with similar efficiencies and processing patterns.     

Prevalence and reporting of near-point binocular convergence and acuity vision deficits in potential research participants

Visual abilities at near-point distances of 200 self-reported normal vision college students were assessed. Results show that normal visual functioning with no deficits is the exception. The most common visual deficits observed involved binocular lateral posture and fusion convergence deficits. Binocular and monocular acuity deficits also had high prevalence rates, although not as prevalent as the binocular convergence deficits. In addition, 1,340 articles published in four major journals from the years 1997-2004 were examined to ascertain the extent to which authors report the visual capabilities of their participants. Reporting of research participant visual abilities by authors using visual stimuli in experiments appears to be lacking. The results are discussed in terms of the potential impact that visual deficits may have on results obtained in experiments in which visual stimuli are used and the importance of reporting the visual assessment tests and procedures used to assess the visual abilities of potential participants.     

like and cross modality recognition in subnormal children

The ability of mentally subnormal children to recognize previously presented visual or verbal stimuli was compared. In “like-modality” procedures they had to recognize words or pictures in the modality in which they had originally been presented. In “cross-modality” procedures the stimulus they had to recognize was in the opposite modality from that which had been used for the first presentation.

In every recognition test the items had to be recognized from among an equal number of novel stimuli. Cross-modality procedures resulted in higher recognition scores. The hypothesis is advanced that this could be accounted for by the necessary translation from one type of sensory image to another in the cross-modality trials, which might minimize over-generalization.     

Communication and crying in newborns

Few studies have analysed newborns’ crying behaviour in relation to the communicative context. In the present study, duration, latency and dysphony of newborns’ cry were analysed in three different communicative conditions: absent, continuous and discontinuous tactile communication. Thirty newborns were randomly assigned to three tactile communicative procedures. Subsequently they were presented with two visual stimuli, face (social-stimulus) and square (non-social-stimulus). The study showed that newborns cried only during visual stimuli presentation both in absent and continuous communication conditions. Newborns with absent communication cried more, with shorter latency and more dysphony than newborns with continuous communication. No significant differences were found in duration, latency and dysphony of newborns’ cry between the two stimuli. Newborns in the discontinuous communicative condition did not cry either during tactile communication or during visual stimuli presentation. Different communicative contexts affected the newborns’ crying behaviour during stimuli presentation. Different interpretations are discussed here in order to explain the results.     

USING COMPLEX AUDITORY—VISUAL SAMPLES TO PRODUCE EMERGENT RELATIONS IN CHILDREN WITH AUTISM

Six participants with autism learned conditional relations between complex auditory‐visual sample stimuli (dictated words and pictures) and simple visual comparisons (printed words) using matching‐to‐sample training procedures. Pre‐ and posttests examined potential stimulus control by each element of the complex sample when presented individually and emergence of additional conditional relations and oral labeling. Tests revealed class‐consistent performance for all participants following training.     

Design and evaluation of a touchscreen apparatus for operant research with pigeons

We developed a touchscreen apparatus for pigeons and conducted a series of experiments that assessed its utility for free-operant procedures. The apparatus incorporated an on-board Windows computer, an electromechanical interface, an amplified speaker, and the touchscreen. We found that merely projecting a virtual key on the screen was insufficient; too many pecks missed the key. Adding a visual target in the center of the key and providing visual feedback for on-key pecks both failed to improve response accuracy. Accuracy was improved by imposing a timeout after off-key pecks or providing a physical boundary around the key. With the physical boundary, response accuracy was comparable to that obtained with conventional plastic keys, and response acquisition via autoshaping also was comparable. Mixing the color elements of the screen's pixels produced color stimuli, but the colors did not function as pure wavelengths of light in tests of stimulus generalization. Both colors and geometric shapes functioned as discriminative stimuli in multiple schedules with variable-interval and extinction components or rich and lean fixed-ratio components. In general, our touchscreen apparatus is a viable alternative to conventional pigeon chambers and increases the experimenter's options for visual stimuli, auditory stimuli, and the number and location of response keys.     

REINFORCER ASSESSMENT FOR CHILDREN WITH DEVELOPMENTAL DISABILITIES AND VISUAL IMPAIRMENTS

We assessed the applicability of two previously developed reinforcer assessment procedures to children with developmental disabilities and visual impairments. Greater differentiation between stimuli was observed with a choice procedure than with a preference procedure. Measurement of compliance and rate of responding in adaptive skill training confirmed that the choice procedure accurately identified reinforcing stimuli. The preference procedure produced false positive predictions of reinforcer efficacy.     

Auditory–Visual stimuli: Effects on derived relations with compound stimuli

This research explored the effect of teaching conditional discriminations with three procedures on the derivation of 36 stimuli relations (derived relations). The stimuli used consisted of three characteristics musical instruments, along with the corresponding picture. In the first experiment six university students were trained with simple stimuli and tested with compound auditory–visual samples; therefore, a one‐to‐many structure was used. In the second experiment, auditory stimuli were replaced by visual stimuli, for the samples used, for new students. A third experiment was implemented with an extra phase of training with compound stimuli for six new students. The structure of the experiments was: pretests (Xbcd–A; Xacd–B; Xabd–C; Xabc–D), training (A–B; A–C; A–D), and posttests (same as pretests). The difference between these conditions was the kind of stimuli used and a new phase of teaching used in condition 3: (Xbcd–A). The results indicate that training with simple stimuli on discriminations that include stimuli that are easy to discriminate from each other (words and sounds) is a sufficient condition for good posttest performance. However, when comparisons are made difficult (words only), participants show better performance on new tests if they have a learning history with compound stimuli.     

Using HyperCard to administer a figural test on the Apple Macintosh

To date, applications of automated assessment techniques in personality testing have largely been limited to objective personality instruments with text stimuli; few assessment applications have involved graphic stimuli. Although projective personality instruments generally include ambiguous graphic or pictorial stimuli, computer applications with these procedures have been limited to automated scoring and interpretation, administration of sentence completion devices employing text stimuli, and the use of mechanical methods rather than computer graphics to display visual stimuli. In the present report, we describe a Macintosh HyperCard application for administering an objective personality test with visual stimuli, the Barron-Welsh Revised Art Scale of the Welsh Figure Preference Test. This test consists of a series of figural stimuli and a binary “like”/“dislike” response format, and it thus represents an administration procedure between standard objective self-report inventories involving text stimuli and a “true”/“false” response or variant, and tests such as the Rorschach or TAT that are both figural and free-response. The HyperCard language provides a variety of promising techniques useful for microcomputer test administration.     

See what you want to see: motivational influences on visual perception

People's motivational states--their wishes and preferences--influence their processing of visual stimuli. In 5 studies, participants shown an ambiguous figure (e.g., one that could be seen either as the letter B or the number 13) tended to report seeing the interpretation that assigned them to outcomes they favored. This finding was affirmed by unobtrusive and implicit measures of perception (e.g., eye tracking, lexical decision tasks) and by experimental procedures demonstrating that participants were aware only of the single (usually favored) interpretation they saw at the time they viewed the stimulus. These studies suggest that the impact of motivation on information processing extends down into preconscious processing of stimuli in the visual environment and thus guides what the visual system presents to conscious awareness.     

Hemisphere dynamics in lexical access: automatic and controlled priming

Hemisphere differences in lexical processing may be due to asymmetry in the organization of lexical information, in procedures used to access the lexicon, or both. Six lateralized lexical decision experiments employed various types of priming to distinguish among these possibilities. In three controlled (high probability) priming experiments, prime words could be used as lexical access clues. Larger priming was obtained for orthographically similar stimuli (BEAK-BEAR) when presented to the left visual field (LVF). Controlled priming based on phonological relatedness (JUICE-MOOSE) was equally effective in either visual field (VF). Semantic similarity (INCH-YARD) produced larger priming for right visual field (RVF) stimuli. These results suggest that the hemispheres may utilize different information to achieve lexical access. Spread of activation through the lexicon was measured in complementary automatic (low probability) priming experiments. Priming was restricted to LVF stimuli for orthographically similar words, while priming for phonologically related stimuli was only obtained in the RVF. Automatic semantic priming was present bilaterally, but was larger in the LVF. These results imply hemisphere differences in lexical organization, with orthographic and semantic relationships available to the right hemisphere, and phonological and semantic relations available to the left hemisphere. Support was obtained for hemisphere asymmetries in both lexical organization and directed lexical processing.     

Comparison at a distance

The visual system is known to contain hard-wired mechanisms that compare the values of a given stimulus attribute at adjacent positions in the visual field; but how are comparisons performed when the stimuli are not adjacent? We ask empirically how well a human observer can compare two stimuli that are separated in the visual field. For the stimulus attributes of spatial frequency, contrast, and orientation, we have measured discrimination thresholds as a function of the spatial separation of the discriminanda. The three attributes were studied in separate experiments, but in all cases the target stimuli were briefly presented Gabor patches. The Gabor patches lay on an imaginary circle, which was centred on the fixation point and had a radius of 5 deg of visual angle. Our psychophysical procedures were designed to ensure that the subject actively compared the two stimuli on each presentation, rather than referring just one stimulus to a stored template or criterion. For the cases of spatial frequency and contrast, there was no systematic effect of spatial separation up to 10 deg. We conclude that the subject's judgment does not depend on discontinuity detectors in the early visual system but on more central codes that represent the two stimuli individually. In the case of orientation discrimination, two naive subjects performed as in the cases of spatial frequency and contrast; but two highly trained subjects showed a systematic increase of threshold with spatial separation, suggesting that they were exploiting a distal mechanism designed to detect the parallelism or non-parallelism of contours.     

Contextual control by function and form of transfer of functions

This study investigated conditions leading to contextual control by stimulus topography over transfer of functions. Three 4-member stimulus equivalence classes, each consisting of four (A, B, C, D) topographically distinct visual stimuli, were established for 5 college students. Across classes, designated A stimuli were open-ended linear figures, B stimuli were circular, C stimuli three-sided, and D stimuli four-sided. Three different computer tasks then were trained with the B stimuli. Differential reinforcement and punishment procedures were then used to establish control over function transfer by the topography of the class members. For Task 1, function transfer, responding to C and D stimuli as subjects had to B stimuli, was reinforced. For Task 2, function transfer was reinforced for C stimuli but punished for D stimuli. For Task 3, function transfer was punished for both C and D stimuli. New equivalence classes were then established and tests for generalized contextual control were presented. All 5 subjects showed generalized contextual control of transfer of functions by stimulus topography. Implications of contextual control over function transfer in natural settings are discussed.     

Hemispheric competence and perceptual confusability

Hemispheric competence in performing easy and difficult letter classification was examined in an exact replication of a previous experiment by Jonides (1979). The present experiment failed to confirm Jonides's finding of right visual field advantage in conditions of perceptual confusability and left visual field superiority when the stimuli were easily discriminable. The results showed a trend in the opposite direction, but no significant interaction. This divergence is discussed with respect to existing evidence and methodological procedures.     

Masking procedures can influence priming effects besides their effects on conscious perception

Masked priming has been employed to study the role of consciousness for different levels of visual processing. However, masking procedures differ systematically between studies. To examine these procedural differences we contrasted priming effects with metacontrast masking, which is often applied in the context of perceptual priming, and priming effects with sandwich pattern masking, frequently used in studies on semantic priming. Results indicate that the amount of masking neither affects perceptual nor semantic priming effects in a semantic categorization task when a metacontrast masking paradigm was used. However, perceptual and semantic priming effects increased with increasing prime visibility when a sandwich pattern masking paradigm was used. Findings suggest that different types of masking procedures affect the processing of the masked stimuli in substantially different ways even if the masking effect on conscious perception of these stimuli is comparable.     

Teaching children with autism spectrum disorder to tact olfactory stimuli

Research on tact acquisition by children with autism spectrum disorder (ASD) has often focused on teaching participants to tact visual stimuli. It is important to evaluate procedures for teaching tacts of nonvisual stimuli (e.g., olfactory, tactile). The purpose of the current study was to extend the literature on secondary target instruction and tact training by evaluating the effects of a discrete‐trial instruction procedure involving (a) echoic prompts, a constant prompt delay, and error correction for primary targets; (b) inclusion of secondary target stimuli in the consequent portion of learning trials; and (c) multiple exemplar training on the acquisition of item tacts of olfactory stimuli, emergence of category tacts of olfactory stimuli, generalization of category tacts, and emergence of category matching, with three children diagnosed with ASD. Results showed that all participants learned the item and category tacts following teaching, participants demonstrated generalization across category tacts, and category matching emerged for all participants.     

Common processes underlie enhanced recency effects for auditory and changing-state stimuli

For some stimuli, dynamic changes are crucial for identifying just what the stimuli are. For example, spoken words (or any auditory stimuli) require change over time to be recognized. Kallman and Cameron (1989) have proposed that this sort of dynamic change underlies the enhanced recency effect found for auditory stimuli, relative to visual stimuli. The results of three experiments replicate and extend Kallman and Cameron's finding that dynamic visual stimuli (that is visual stimuli in which movement is necessary to identify the stimuli), relative to static visual stimuli, engender enhanced recency effects. In addition, an analysis based on individual differences is used to demonstrate that the processes underlying enhanced recency effects for auditory and dynamic visual stimuli are substantially similar. These results are discussed in the context of perceptual grouping processes.