Development of arousal-modulated visual preferences in early infancy.

Looking preferences to visual temporal frequencies between 1 and 8 Hz were studied longitudinally at 3 ages (newborn, 1 month, 4 months; N?=?77) in 3 conditions: less aroused (after feeding), more aroused-internal (before feeding), and more aroused-external (after feeding with 8 Hz visual stimulation before each trial). Replicating and extending previous results, a strong interaction between arousal level and stimulus frequency was found at newborn and 1 month. Infants preferred faster stimuli when less aroused and slower stimuli when more aroused, with no differences between the 2 more aroused conditions even though produced by different operations. At 4 months, the interaction with arousal no longer existed; faster stimuli were preferred in all conditions. Thus, after the transition in visual behavior normally occurring at 2–3 months, arousal no longer played a major role, possibly as a result of emergent cortical sensory-specific attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Feeding-based arousal effects on visual recognition memory in early infancy.

Arousal effects on a 1-trial visual recognition paired-comparison task were studied at newborn, 1-month, and 4-month test ages. Infants were tested before and after feeding, with arousal assumed to be lower after feeding. Newborns and 1-month-olds shifted from a familiarity preference before feeding to a novelty preference after feeding. A control group tested only after feeding confirmed that this shift was not due to increased stimulus exposure from the prefeeding test. By 4 months, infants showed novelty preferences independent of feeding. This age by arousal interaction for recognition memory extends previous knowledge by including endogenous arousal with age, stimulus, and length of exposure as contributors to familiarity–novelty preferences. It also extends and provides converging evidence for arousal effects on visual attention in early infancy found previously with preferential looking. A shift from subcortical to cortical dominance is supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory frequency discrimination in infancy.

Investigated the ability of 14 5–8 mo olds and 5 college students to detect changes in the frequency of pure tones. A head turn for visual reinforcement technique was used to obtain difference thresholds for infants and adults at 1,000, 2,000, and 3,000 Hz. With signals presented at 70 db above adult detection thresholds, infants reliably detected frequency changes on the order of 2%, whereas adults detected changes of about 1%. Data confirm previous findings indicating that infants can distinguish different frequencies and can make relatively fine discriminations. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cross-modal equivalence in early infancy: Auditory–visual intensity matching.

To examine the hypothesis that young infants ignore differences between lights and sounds and instead respond to auditory and visual stimuli as more or less similar depending on their intensity, a cardiac habituation/dishabituation method with a test for stimulus generalization was employed. In 2 experiments, a total of 40 3-wk-old Ss were repeatedly presented with white-light followed by white-noise stimuli of different intensities. A U-shaped relationship between magnitude of cardiac response (CR) and loudness was found. In view of previous findings that without prior visual stimulation a monotonic increase in CR to the same range of auditory stimuli results, this finding of a significant quadratic relationship with loudness suggests that Ss were responding to the auditory stimuli in terms of their similarity to the previously presented visual stimulus. A separate group of 14 infants presented with a more intense visual stimulus exhibited a shift in the intensity at which a minimal CR occurred. Results of a study with 31 adults did not show any systematic relationship between CR and loudness, indicating that unlike infants, adults do not spontaneously make cross-modal matches of intensity. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory for multiple visual ensembles in infancy.

The number of individual items that can be maintained in working memory is limited. One solution to this problem is to store representations of ensembles that contain summary information about large numbers of items (e.g., the approximate number or cumulative area of a group of many items). Here we explored the developmental origins of ensemble representations by asking whether infants represent ensembles and, if so, how many at one time. We habituated 9-month-old infants to arrays containing 2, 3, or 4 spatially intermixed colored subsets of dots, then asked whether they detected a numerical change to one of the subsets or to the superset of all dots. Experiment Series 1 showed that infants detected a numerical change to 1 of the subsets when the array contained 2 subsets but not 3 or 4 subsets. Experiment Series 2 showed that infants detected a change to the superset of all dots no matter how many subsets were presented. Experiment 3 showed that infants represented both the approximate number and the cumulative surface area of these ensembles. Our results suggest that infants, like adults (Halberda, Sires, & Feigenson, 2006), can store quantitative information about 2 subsets plus the superset: a total of 3 ensembles. This converges with the known limit on the number of individual objects infants and adults can store and suggests that, throughout development, an ensemble functions much like an individual object for working memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Change in visual memory following discrimination learning.

Studied visual recognition memory for the size of circles for evidence of active memory change in 3 experiments with 34 paid volunteers and 83 undergraduates. In Exp. I the remembered difference in size between 2 circles which had been discriminated on the basis of size increased, while the remembered difference in size between the same 2 circles discriminated on the basis of brightness did not. In Exp. II, the remembered size of the smallest of 4 circles discriminated by size changed from 1 day to 1 wk. Each S in Exp. III inspected either 1 or 2 circles and was asked to remember their size. There was more memory distortion when 2 circles were remembered, but the distortion did not change over time. The evidence suggests that memory will actively change after a visual discrimination task. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory-based automaticity in the discrimination of visual numerosity.

In the development of memory-based models of automaticity, it is crucial to specify the nature of the memory representation. Seven experiments with 94 students use a counting task to determine whether a feature (i.e., identity, color, or orientation) is explicitly represented in memory. It is assumed that the degree of transfer to a pattern differing on one feature is determined by that feature's importance in supporting skilled performance. Exp 1 determined the practice necessary to obtain automaticity. In Exps 2a, 3a, and 4a, which investigated the nature of the representation after extended practice, changing neither the identity nor color of elements had strong effects on transfer, but changing pattern orientation did impair memory retrieval, thus suggesting that for the counting task, pattern orientation is more important than element identity or color. Exps 2b, 3b, and 4b replicated these results after limited practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decision processes in visual discrimination of line orientation.

The contribution of decision factors to the meridional variations in line orientation discrimination (OD) was determined for 2-alternative forced-choice experimental designs. With K. O. Johnson's (1980) formalization of decision processes in discrimination tasks, 3 decision factors were identified: decision rule, memory variance, and criterial noise. Exp I (with 13 Ss) showed the effect of experimental design on OD to be similar at horizontal and oblique standard orientations, indicating that the meridional variations in OD were not due to a decision rule anisotropy. In Exp II (with 5 Ss) the effect of the interstimulus interval was also found to be similar at both standard orientations, suggesting that the memory variance is isotropic in the orientation domain. Exps III and IV (with a total of 7 Ss) supported the hypothesis that the meridional variations in OD are not due to a criterial noise anisotropy. Results strongly suggest that the oblique effect in OD is due to sensorial factors rather than to decision factors. Therefore, they further support the hypothesis linking the anisotropy of the preferred orientation distribution of Area 17-S cells (a single physiologically defined class of cells in the primary visual cortex) and the meridional variations in OD. (58 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual discrimination by cats given lesions of visual cortex in one or two stages in infancy or in one stage in adulthood.

Sparing of visual function was studied in cats with bilateral cortical damage to Areas 17 and 18 and most of Area 19. Cats with lesions made in 2 stages, on Postnatal (P) Days 3 and 6, in 1 stage on P6, or in 1 stage in adulthood were compared with sham-operated controls on 10 visual discrimination tasks. On some tasks, both groups of cats that underwent surgery as infants showed considerable sparing of function compared with cats that had surgery as adults; the latter group showed a marked impairment. However, on several of the discriminations, 2-stage lesions permitted almost total sparing of pattern vision, whereas 1-stage lesions made neonatally were almost as debilitating as those incurred in adulthood. The findings suggest that differential behavioral consequences can follow physiological or anatomical changes, or both, that occur within a 4-day neonatal interoperative period. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive learning in infancy and early childhood.

The stress on genetic factors in early cognitive development has led to the amassing of a considerable body of normative data. However, there has been little interest in determining the scope and complexity of learning possible during the initial phases of development. Research literature and theoretical orientations are presented to show the potential importance of studying early cognitive learning. (201 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lack of power enhances visual perceptual discrimination.

Powerless individuals face much challenge and uncertainty. As a consequence, they are highly vigilant and closely scrutinize their social environments. The aim of the present research was to determine whether these qualities enhance performance in more basic cognitive tasks involving simple visual feature discrimination. To test this hypothesis, participants performed a series of perceptual matching and search tasks involving colour, texture, and size discrimination. As predicted, those primed with powerlessness generated shorter reaction times and made fewer eye movements than either powerful or control participants. The results indicate that the heightened vigilance shown by powerless individuals is associated with an advantage in performing simple types of psychophysical discrimination. These findings highlight, for the first time, an underlying competency in perceptual cognition that sets powerless individuals above their powerful counterparts, an advantage that may reflect functional adaptation to the environmental challenge and uncertainty that they face. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The effect of psychopathology on visual discrimination.

"Perceptual and motor aspects of the Bender-Gestalt Test performance were compared for 4 groups of Ss: 10 student nurses, 10 acute schizophrenic patients, 10 chronic schizophrenic patients, and 10 patients hospitalized for neurological reasons… . After the Ss had obtained equal experiences with the Bender designs by reproducing them under memory and copy conditions, a perceptual multiple-choice test was administered under memory and matching conditions. Results indicate that there are marked differences in perceptual accuracy between the 4 groups: the control population was most accurate, with the acute schizophrenic, chronic schizophrenic, and neurological patients less proficient in that order." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Septal lesions in rats produce reversal deficits in a simultaneous visual discrimination.

Trained 54 rats with septal lesions and their operated controls on a 2-choice simultaneous brightness discrimination problem and its reversal using a correction procedure in a maze with 4 sequential choice points. Rats with septal lesions were deficient in the reversal of this brightness discrimination. However, this deficit was seen only in a measure of repeated errors and was considerably altered by forced preexposure to selected cues involved in discrimination. Thus, perseveration was seen, as measured by repeated errors, even though rats with lesions reached criterion in the same number of trials as operated controls. Findings emphasize the critical nature of stimulus conditions, response measures, and the history of the animal in determining the effects of brain damage on behavior. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Violation of expectancy and frustration in early infancy.

Instrumental responses to both learning and extinction were examined in a group of infants aged 2–8 months. Eighty infants, divided equally among 4 age groups (2, 4, 6, and 8 months), participated in a contingency learning task. Forty-eight Ss received an audiovisual stimulus contingent on arm movement, and 32 Ss served as a yoked control group. Findings indicated that (a) infants in the contingent group showed a significant increase in their rate of arm pulling as a function of contingent stimulation; (b) with the cessation of stimuli during extinction, contingent subjects at all ages showed a significant increase in response rate from the learning phase; and (c) the ability to learn an instrumental response and reactivity to the violation of a learned expectancy were not related to temperament differences. The results indicate that exposure to extinction, a period in which the infant's expectancy regarding contingent outcomes is violated, produces responsivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in visual recall memory following discrimination learning.

Trained 100 undergraduates to discriminate among 4 visual stimuli on either 1 of the 2 dimensions which differentiated them: area (large or small circles) or dot density (thickly or lightly filled with dots). Recall was tested immediately or after delay of 4 hrs, 1 day, 1 wk, or 2 wks by having each S draw all 4 stimuli at 1 of these intervals. Differences in recall along the dimension which was discriminated were exaggerated relative to differences on the other dimension. The relative exaggeration was large immediately following testing, declined to a minimum after 1 wk, and increased again after 2 wks. Results are consistent with previously reported changes in visual recognition memory, and suggest a 2-process interpretation. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Competition and sharing of processing resources in visual discrimination.

Discrimination thresholds for spatial frequency and contrast tested individually were compared with dual discrimination of contrast and spatial frequency, and dual discrimination of 2 contrast or spatial frequency components. The components were presented overlapping, forming a compound grating or as side-by-side simple gratings. When observers had to judge contrast and spatial frequency simultaneously, discrimination thresholds increased by an amount predicted by a model of stimulus uncertainty for orthogonal dimensions (1.7); when they had to judge 2 frequency or contrast components, discrimination thresholds increased by a factor of 3–6 compared with the single-judgment task. The relative spatial location of the components did not interact with task complexity. The results are consistent with a model assuming a set of parallel special-purpose attentional mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Set size, novelty, and visual pop-out in infancy.

The effects of set size and novelty on visual pop-out in 6-month-old infants was assessed in a perceptual-identification (memory reactivation) paradigm in which infants, trained and tested in their own homes, viewed a mobile containing a unique novel or familiar object amidst different numbers of familiar or novel distractors, respectively. Unique objects of both types popped out at all set sizes except the largest, where there was modest evidence that familiar distractors speeded processing (Experiment 1). When the proportion of familiar targets in a display of intermediate set size was increased, however, infants no longer detected the familiar target (Experiment 2). These findings offer additional support for the proposition that visual pop-out in infants and adults is the same phenomenon. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Detection of intermodal proprioceptive–visual contingency as a potential basis of self-perception in infancy.

Four studies investigated 29 3-mo-old (Exp IV) and 60 5-mo-old (Exps I–III) infants' capacity to detect proprioceptive–visual relations uniting self-motion with a visual display of that motion. Previous research has shown that 5-mo-old infants can detect the invariant relationship between their own leg motion and a video display of that motion. The 1st 3 experiments showed that the 5-mo-olds discriminated between a perfectly contingent live display of their own leg motion and a noncontingent display of self or a peer. They showed this discrimination by preferential fixation of the noncontingent display. This effect was evident even when an S's direct view of his/her own body was occluded, eliminating video image discrimination on the basis of an intramodal visual comparison between the sight of self-motion and the video display of that motion. These results suggest that the contingency provided by a live display of one's body motion is perceived by detecting the invariant intermodal relationship between proprioceptive information for motion and the visual display of that motion. The detection of these relations may be fundamental to the development of self-perception in infancy. Although 3-mo-olds did not show significant discrimination of the contingent and noncontingent displays in Exp IV, they did show significantly more extreme looking proportions to the 2 displays than did the 5-mo-olds. This may reflect the infant's progression from a self- to a social orientation. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)