The ontogenesis of an auditory localization response from birth to four months of age.

Research on the early development of auditory localization responses is reviewed, and the existence of a U-shaped developmental function is described. It has been reported that many newborns turn toward off-centered sound sources reliably at birth and will perform well for approximately the 1st mo of life, poorly during the 2nd and 3rd mo, and well again during the 4th mo. This trend was confirmed in 3 of 4 infants who were tested extensively throughout their early months. The 4th S failed to show reliable orientation toward sounds until the 4th mo of life. During the period of temporary performance decrement, attempts to reinstate reliable responding by either introducing meaningful acoustic stimuli or eliminating possible auditory-visual conflicts were not successful. (French abstract) (48 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cardiac and behavioral responses to repeated tactile and auditory stimulation by preterm and term neonates.

Auditory stimuli (a buzzer and rattle) and a tactile stimulus (a plastic filament) were repeatedly presented to 18 term and 18 preterm infants. Both groups initially responded to all stimuli with increased limb movements and heart rate acceleration. However, only the term infants responded to stimulus repetition by decreasing both cardiac and behavioral responses. In addition, they differentially responded to the 3 stimuli and showed response recovery in both systems. Since a behavioral response decrement was observed without a cardiac response decrement in the preterm group, a 2nd experiment was conducted. Heart rate change during the sucking activity of Exp II revealed an integration between autonomic and motor responsivity of preterm infants comparable to that of term newborns. The lack of cardiac–behavioral response integration during Exp I is discussed in the context of state differences between preterm and term infants as well as potential immaturity or some insult experienced by the preterm infants. The stimulus discrimination and habituation demands of Exp I may have overtaxed the preterm infants' ability to maintain response integration. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A model for conceptual processing of naturalistic scenes.

Reports on 3 experiments, with 251 undergraduates, that examine serial position effects for rapidly-presented naturalistic scenes. The experiments provide a basis for comparison with the U-shaped serial position curve and list-length effect that typically result from verbal learning experiments. In contrast to the U-shaped verbal serial position function, results show a flat function at the beginning serial positions and a recency effect that is small and limited to the last serial position. There is also a set-size effect. Results suggest that the processing leading to a memory representation for visual stimuli such as pictures and linguistic stimuli such as words is qualitatively dissimilar. The findings can be accounted for by a serial processing model whose main parameter is the probability that the subject will switch attention from one picture to the next. (French abstract) (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)     

Age- and sex-related differences in left- and right-hemisphere processing by learning disabled children.

Age and sex differences in left- and right-hemisphere processing were assessed with 2 dichotic listening tasks in a sample of 48 control and 48 learning-disabled (LD) children ranging in age from 6 yrs 9 mo to 12 yrs 4 mo. Children were presented with consonant–vowel syllables (CVs) and simple square-wave and complex square-wave tones. Neither age nor sex differences in response accuracy or lateralized processing of CV stimuli were evident for control children. Borderline significance was obtained for tonal stimuli. In contrast, CV stimuli elicited a bilateral response in younger LD children, and tonal stimuli elicited a bilateral response in all LD children. Furthermore, control children were oppositely lateralized for verbal and nonverbal stimuli, whereas LD Ss exhibited a general processing bias to the same hemisphere. These data support the theory that LD children may lack the necessary functional specialization required for lateralized processing of such stimuli. In addition, these data do not fully support the developmental invariance hypothesis and may even suggest a putative right-hemisphere or bilateral processing deficiency in LD children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Liking and Memory for Musical Stimuli as a Function of Exposure.

Three experiments examined changes in liking and memory for music as a function of number of previous exposures, the ecological validity of the music, and whether the exposure phase required focused or incidental listening. After incidental listening, liking ratings were higher for music heard more often in the exposure phase and this association was stronger as ecological validity increased. After focused listening, liking ratings followed an inverted U-shaped function of exposure for the most ecologically valid stimuli (initial increases followed by decreases), but this curvilinear function was attenuated or nonexistent for less valid stimuli. In general, recognition improved as a function of previous exposure for focused listeners, but the effect was attenuated or absent for incidental listeners. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lateralized word recognition: Assessing the role of hemispheric specialization, modes of lexical access, and perceptual asymmetry.

The processing advantage for words in the right visual field (RVF) has often been assigned to parallel orthographic analysis by the left hemisphere and sequential by the right. The authors investigated this notion using the Reicher-Wheeler task to suppress influences of guesswork and an eye-tracker to ensure central fixation. RVF advantages obtained for all serial positions and identical U-shaped serial-position curves obtained for both visual fields (Experiments 1–4). These findings were not influenced by lexical constraint (Experiment 2) and were obtained with masked and nonmasked displays (Experiment 3). Moreover, words and nonwords produced similar serial-position effects in each field, but only RVF stimuli produced a word-nonword effect (Experiment 4). These findings support the notion that left-hemisphere function underlies the RVF advantage but not the notion that each hemisphere uses a different mode of orthographic analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sustained attention in adulthood: A unique, large-sample, longitudinal and multicohort analysis using the Mackworth Clock-Test.

A cross-sectional sample of men (n?=?177) tested in 1962–1964, and men (n?=?188) and women (n?=?113) tested in 1980–1984, and a longitudinal sample (n?=?53) of men tested in 1962–1964 and 1980–1984, were used to investigate age differences and 18-year age changes on a 62-min sensory vigilance task that made virtually no demand on memory, the Mackworth Clock-Test. Age differences and changes in the vigilance decrement were also examined. No age differences or changes were obtained for detection accuracy. Target response time showed significant age-related 18-year longitudinal changes and one significant cross-sectional age difference; the overall age effect was of a U-shaped function with a minimum at middle age. Age differences and changes were obtained in a measure of arousal: skin potential response latency; the overall age effect was also consistent with a U-shaped function. There was little consistent evidence of a differential effect of age on the vigilance decrement. Outcomes contradictory to Surwillo and Quilter (1964) and Quilter, Giambra, and Benson (1983) are reconciled through additional statistical analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric changes in information processing during development.

Hemispheric processing of visually presented words and pictures was examined in 3 groups of Ss with mean ages of 8 yrs 8 mo, 12 yrs 3 mo, and 27 yrs 9 mo (154 Ss). Pictorial or symbolic stimuli were presented singly to either the right or left visual hemifield. Ss had to decide whether the 1st stimulus in a pair matched the 2nd stimulus. The major results were that (a) age groups differed in the strength of lateral differences, and (b) for all age groups, the right hemisphere was significantly faster in processing unmatched stimuli. Results suggest that lateral specialization of the left hemisphere is not complete until adolescence and that over the age range tested, the left hemisphere becomes progressively more specialized for the processing of matched data. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Free-operant avoidance behavior in rats with lateral septal lesions: Effect of shock intensity

The purpose of experiment 1 was to examine the relationship between shock intensity and normal rats' free-operant (Sidman) avoidance performance on a 3-component, multiple schedule. The results showed an inverted U-shaped relation between response rate and shock intensity, but no consistent relation between shock rate and shock intensity was found. Experiment 2 showed that lateral sptal lesions produced a bidirectional change in reactivity to electric shock. An increased reactivity was observed in the initial sessions starting on the 11th day after the surgery, while a reduced reactivity was observed in the final sessions when stable performance had been reacquired. These changes were not a function of the waning of general hyperreactivity with post-operative recovery: the septal lesions in this study did not produce any "sham rage". From 40 to 80% of the variance in response rates was accounted for by this bidirectional change in the reactivity to shock.     

Time-linked impairment in schizophrenic reaction time performance.

Reports on the disruptive influence of uncertain visual probe stimuli on schizophrenic reaction time performance as a function of both the time since the onset of the probe stimuli and the pathology level of the Ss. Two studies were conducted, using 32 process schizophrenics, 16 reactive schizophrenics, 16 nonschizophrenic patients (alcoholic, immature personality, and depression diagnoses), and 16 normal controls. Mean ages of Ss ranged from 28.2 to 37.1 yrs. Probe trials were imbedded within standard series of regular reaction time trials. Both process and reactive schizophrenics were impaired by this stimulation on trials with only a 1-sec preparatory interval. Process schizophrenics showed impairment at the longest (9-sec) trials following recovery at midrange durations. The midrange recovery and long trial impairment of the process schizophrenics was a pattern strongly related to degree of pathology. The same U-shaped pattern—early and late impairment with intermediate recovery—and a similar relationship of the reaction time pattern to pathology level were found again in a 2nd sample of process schizophrenics who were given less intense visual stimulation on the probe trials. The U-shaped patterns obtained for the process schizophrenics in both studies are thought to reflect inadequate modulation of inhibitory controls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delay classical conditioning in young and older rabbits: Initial acquisition and retention at 12 and 18 months.

Classical conditioning of the nictitating membrane-eyeblink response in young (age 7 mo) and older (age 36 mo) New Zealand white rabbits in a delay paradigm with 400-msec CS–unconditioned stimulus/stimuli (UCS) interval was examined for initial acquisition and retention. Older animals required significantly more acquisition trials to reach learning criterion. Age differences in acquisition were temporary. Older rabbits responded at a level comparable to that of young rabbits such that total performance over the 630 trials of acquisition was not different. Rabbits in the explicitly unpaired control groups exhibited no age differences in unconditioned response (UCR) amplitude or latency measures. 12- and 18-mo retests demonstrated no significant age effects on retention. Patterns of retention differed between age groups. Older rabbits required fewer trials to obtain the learning criterion at each phase of testing. Younger rabbits maintained a stable performance throughout training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivational climate and intrinsic motivation of young basketball players

Properties of short-term memory for faces (Exp. 1) were investigated in 40 young and 30 elderly persons and compared with short-term memory for non-verbal shapes (Exp. 2) with 30 new persons in a young group and an elderly one. Young subjects displayed a U-shaped curve for both kinds of stimuli, and elderly subjects displayed a U-shaped curve, but the recency effect was abolished for faces (in one condition). This suggests a possible specific short-term store for faces.     

Re-examination of residual arousal as an explanation of aftereffects: Frustration tolerance versus response speed.

Three experiments, with 98 undergraduates, investigated the effects of increasing task difficulty and noise intensity on postnoise persistence on the Feather tolerance for frustration puzzles. In Exp I, greater persistence occurred both after exposure to moderate noise levels (55 db [A]) and an easy perceptual-motor task and after high noise levels (90 db [A]) and a more difficult task. The same pattern of persistence was obtained in Exp II, with more attempts to solve the Feather puzzles occurring after moderate noise and an easy cognitive task and after loud noise and a more difficult cognitive task. In Exp III, a modified Feather task was presented with instructions to determine solvability. A similar U-shaped relationship was obtained, with longer correct response times to unsolvable puzzles following low noise and high noise. Such aftereffect patterns are more easily explained as the result of residual arousal than of frustration tolerance. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of intuitive theories of motion: Curvilinear motion in the absence of external forces.

96 4.5–12 yr olds and 20 college students were asked to draw the path a ball would take when exiting a curved tube. As in previous studies, many Ss erroneously predicted curvilinear paths. However, a clear U-shaped curve was evident in the data. Preschoolers and kindergartners performed as well as college students, whereas school-aged Ss were more likely to make erroneous predictions. Results of a 2nd study, with 24 preschoolers (mean age 5 yrs 2 mo), suggest that the youngest children's correct responses could not be attributed to response biases or drawing abilities. This developmental trend suggests that the school-aged children are developing intuitive theories of motion that include erroneous principles. Results are related to the "growth errors" found in other cognitive domains and to the historical development of formal theories of motion. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lens induced aniso-accommodation

Despite the evidence for consensual accommodation in response to consensual accommodative stimuli, only a few studies have investigated the binocular accommodative response to unequal (aniso) accommodative stimuli. Past studies investigating an unequal binocular accommodative response (aniso-accommodation) to aniso-accommodative stimuli have been limited by viewing conditions and measurement technique making the results, which were equivocal, difficult to interpret. This investigation addressed these limitations by the following design parameters: (1) monocular dichoptic blur cuese were provided in the binocular stimulus target to provide subjects feedback on their aniso-accommodative response and to alert the investigator of a monocular blur suppression response; (2) a training period was provided; (3) in the subjective method, each eye's stigma was positioned near the dichoptic letter viewed by the other eye. By this method, a true aniso-accommodative response could be differentiated from successive consensual responses; (4) a large range of aniso-accommodative stimuli was used, 0.50-3.0 D, presented in incremental steps of 0.5 D, allowing measurement of an average 0.75 D aniso-accommodative response for the highest (3.0 D) aniso-accommodative stimulus; (5) aniso-accommodation was measured as a function of viewing distance. For four of seven subjects, the gain of the aniso-accommodative response was significantly greater at near than at far viewing distances; (6) aniso-accommodation was confirmed objectively with measures of the response to steady state and step aniso-accommodative stimuli, using a binocular SRI Dual Purkinje Eye Tracker Optometer System. The aniso-accommodative response to step stimuli showed a very long latency period (about 11 s) and a response time of 4.5 s. A potential benefit of aniso-accommodation would be to overcome small amounts of uncorrected anisometropic refractive error. This would preserve fine stereo acuity which is impaired by unequal intraocular image contrast. Aniso-accommodation also may provide an appropriate efferent feedback signal for each eye's unique refractive error which could be used to guide developmental isometropization (attainment of equal refractive error in the two eyes.).     

Selective processing of visual alcohol cues in abstinent alcoholics: an approach-avoidance conflict?

When symptomatic individuals selectively attend to emotionally relevant stimuli, the ability to shift attention away from such material is impaired. Subjects may, however, seek to avoid further processing of these stimuli, which would facilitate attentional shifts. This was examined in a group of abstinent alcoholics' responses to stimuli related to alcohol. Eight alcohol and eight neutral words served as cues in a covert attention task. The cues were either valid (2/3 of trials) or invalid (1/3 of trials) indicators of where a response target would appear after 100 or 500 milliseconds. The short interval was expected to interact with an initial approach toward the alcohol word, while the long interval would interact with a subsequent avoidance of the stimulus. As predicted, the alcoholics showed slower reaction times (RTs) to targets invalidly cued by alcohol words in the short interval, reflecting increased difficulties to shift attention. However, the alcoholics demonstrated faster RTs to targets invalidly cued by the alcohol words in the long interval. This indicates that the alcohol cue elicited emotional associations that, subsequent to initial stimulus identification, trigger an interrupting function of the attentional system.     

Effects of temporal integration on the shape of visual backward masking functions.

Many studies of cognition and perception use a visual mask to explore the dynamics of information processing of a target. Especially important in these applications is the time between the target and mask stimuli. A plot of some measure of target visibility against stimulus onset asynchrony is called a masking function, which can sometimes be monotonic increasing but other times is U-shaped. Theories of backward masking have long hypothesized that temporal integration of the target and mask influences properties of masking but have not connected the influence of integration with the shape of the masking function. With two experiments that vary the spatial properties of the target and mask, the authors provide evidence that temporal integration of the stimuli plays a critical role in determining the shape of the masking function. The resulting data both challenge current theories of backward masking and indicate what changes to the theories are needed to account for the new data. The authors further discuss the implication of the findings for uses of backward masking to explore other aspects of cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric priming by meaningful and nonmeaningful symbols in language-trained chimpanzees (Pan troglodytes): Further evidence of a left hemisphere advantage.

Hemispheric priming was examined in 3 language-trained chimpanzees (Pan troglodytes) using a simple reaction time (RT) paradigm. Ss were required to hold down a response button until the occurrence of a response cue. A warning stimulus was presented to either the left visual field or the right visual field (RVF) before the response cue occurred. No warning stimulus was presented on control trials. The warning stimuli were geometric communicative symbols from 2 semantic categories: food and tools. A 3rd set of warning stimuli were familiar geometric symbols. Dependent measures included RT and the number of false-positive responses. RT data indicated an RVF advantage in priming when the warning stimuli were food or tool symbols. No significant visual half-field differences were found for familiar symbols, but a trend toward an RVF advantage was observed. These effects were enhanced when Ss responded with their left hand. False-positive data also indicated an RVF advantage for the food and tool warning stimuli. The data indicate that hemispheric asymmetries for processing communicative symbols are present in language-trained chimpanzees. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Red-green and achromatic temporal filters: a ratio model predicts contrast-dependent speed perception

We simultaneously measured detection and identification performance by using isoluminant red-green (RG) and achromatic flickering stimuli and fitted these data with a modified line-element model that does not make high-threshold assumptions. The modeling shows that detection and identification data are adequately described by postulating only two underlying temporal filters each for RG and achromatic vision, even when more than two threshold classifications are evident. We use a spatial frequency of 1.5 cycles per degree (c/deg) and compare the derived temporal impulse response functions with those obtained previously with the use of 0.25 c/deg stimuli under otherwise identical conditions [J. Opt. Soc. Am. A 13, 1969 (1996)]. We find that at 1.5 c/deg the luminance impulse response functions peak later and integrate out to longer times compared with those measured at 0.25 c/deg. For RG stimuli, although their relative overall sensitivities change, the impulse response functions are similar across spatial frequency, indicating a constancy of chromatic temporal properties across spatial scales. In a second experiment, we measured RG and achromatic flicker discrimination over a wide range of suprathreshold contrasts. These data suggest a common nonlinear contrast response function operating after initial temporal filtering. Using a ratio model of speed perception in which both RG and achromatic filters are combined at a common motion site, we can predict (1) the perceived slowing of RG stimuli compared with the perceived drift of achromatic drifting stimuli, (2) the contrast dependency of speed perception for RG and achromatic drifting stimuli, and (3) how this dependency changes with base speed. Thus we conclude that there is no need to postulate separate mechanisms for fast and slow motion [Nature (London) 367, 268 (1994)], since a unified ratio model can explain both RG and achromatic contrast-speed dependency.