Newborns' preference for faces: What is crucial?

Three experiments investigated whether the presence of more elements in the upper part of a configuration (i.e., up-down asymmetry) plays a role in determining newborns' preference for facelike patterns. Newborns preferred a nonfacelike stimulus with more elements in the upper part over a nonfacelike stimulus with more elements in the lower part (Experiment 1), did not show a preference for a facelike stimulus over a nonfacelike configuration equated for the number of elements in the upper part of the configuration (Experiment 2), and preferred a nonfacelike configuration located in the upper portion of the stimulus over a facelike configuration in the lower portion of the pattern (Experiment 3). Results demonstrated that up-down asymmetry is crucial in determining newborns' face preference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Newborns discriminate schematic faces from scrambled faces.

Examined newborn attention to, and discrimination of, facelike patterns in 3 experiments employing 35 one- to three-day-old infants. Differential eye tracking and head turning to three moving stimuli (a schematic face, a scrambled face, and a luminance-matched blank) were measured in 2 of the 3 experiments. The Ss turned their eyes and heads farther to follow patterned stimuli, containing facelike features, than to a luminance-matched blank, but they did not turn farther to a stimulus with the features arranged in a facelike manner compared to features scrambled. A 3rd experiment tested Ss' ability to discriminate between the facelike and scrambled face patterns. Using an infant-controlled procedure, Ss showed similar initial fixation times and similar numbers of trials to reach a 60% response decrement criterion to both patterned stimuli. Following habituation, novelty responding indicated that the Ss discriminated between the schematic face and the scrambled face patterns. Although Ss did not show a preference for a facelike stimulus compared to a features-scrambled pattern in the present experiments, they could discriminate the two patterns based on the internal arrangement of the facial features. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preferential orienting to faces in newborns: A temporal–nasal asymmetry.

It has been proposed that newborns' preferential orienting to faces is primarily controlled by a subcortical mechanism. As an index of subcortical, extrageniculate mediation, the asymmetry between the temporal and nasal hemifields was exploited. In Experiment 1, under monocular viewing conditions, newborns were presented with a pattern that had 3 blobs in the appropriate locations for the eyes and the mouth or a pattern that had an inverted position of the blobs. Results showed that newborns preferentially oriented to the facelike pattern only when it was presented in the temporal hemifield. In Experiment 2, both patterns had the blobs in the inverted position. For one pattern the blobs were black, and for the other they were striped. Newborns preferentially oriented to the striped blobs in either hemifield. The results support the hypothesis that in newborns, preference for facelike patterns reflects the activity of a subcortical mechanism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus energy does not account for 2-month-olds' face preferences.

We examined the determinants of 2-month-olds' preferences among facelike and abstract patterns. Observed preferences were compared with the predictions of two preference models—one based on stimulus energy (as measured by the amplitude spectrum) and the other based on stimulus structure (as measured by the phase spectrum). It is known that the phase spectrum is the primary determinant of perceived identity to adults. Twenty-five 2-month-olds saw six pairings of four patterns: a schematic face, a lattice, a pattern composed of the amplitude spectrum of the lattice and the phase spectrum of the face, and a pattern composed of the amplitude spectrum of the face and the phase spectrum of the lattice. Only patterns with the face's phase spectrum look facelike to adults. Unlike the preferences of newborns (Kleiner, 1987), 2-month-olds' preferences could be predicted from the phase spectrum but not from the amplitude spectrum. In other words, the 2-month-olds preferred the patterns that looked facelike to adults. These results offer clear evidence that 2-month-olds' preferences for facelike patterns are not governed by stimulus energy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Further evidence for hierarchical chunking in rat spatial memory.

In Experiment 1, rats were given a test to determine the order of preference among 3 types of food. Two groups of rats then were trained on a 12-arm radial maze in Experiment 2, with the 3 foods placed in fixed-arm locations for 1 group and in locations that varied randomly across sessions for the other group. The results replicated those of Dallal and Meck (1990) by showing faster learning and more clustering of arm choices by food type in the fixed locations group than in the random-locations group. Two further experiments were performed to test the chunking hypothesis. Observations of working memory in Experiment 3 and the reorganization of reference memory in Experiment 4 both supported the chunking hypothesis by showing superior spatial memory and arm chunking by food type when chunk integrity was maintained than when it was compromised. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Directed attention prolongs the perceived duration of a brief stimulus

Stelmach, Herdman, and McNeil (1994) suggested recently that the perceived duration for attended stimuli is shorter than that for unattended ones. In contrast, the attenuation hypothesis (Thomas & Weaver, 1975) suggests the reverse relation between directed attention and perceived duration. We conducted six experiments to test the validity of the two contradictory hypotheses. In all the experiments, attention was directed to one of two possible stimulus sources. Experiments 1 and 2 employed stimulus durations from 70 to 270 msec. A stimulus appeared in either the visual or the auditory modality. Stimuli in the attended modality were rated as longer than stimuli in the unattended modality. Experiment 3 replicated this finding using a different psychophysical procedure. Experiments 4-6 showed that the finding applies not only to stimuli from different sensory modalities but also to stimuli appearing at different locations within the visual field. The results of all six experiments support the assumption that directed attention prolongs the perceived duration of a stimulus.     

Spatial frequency discrimination: visual long-term memory or criterion setting?

A long-term sensory memory is believed to account for spatial frequency discrimination when reference and test stimuli are separated by long intervals. We test an alternative proposal: that discrimination is determined by the range of test stimuli, through their entrainment of criterion-setting processes. Experiments 1 and 2 show that the 50% point of the psychometric function is largely determined by the midpoint of the stimulus range, not by the reference stimulus. Experiment 3 shows that discrimination of spatial frequencies is similarly affected by orthogonal contextual stimuli and parallel contextual stimuli and that these effects can be explained by criterion-setting processes. These findings support the hypothesis that discrimination over long intervals is explained by the operation of criterion-setting processes rather than by long-term sensory retention of a neural representation of the stimulus.     

The distractor frequency effect in picture–word interference: Evidence for response exclusion.

In 3 experiments, subjects named pictures with low- or high-frequency superimposed distractor words. In a 1st experiment, we replicated the finding that low-frequency words induce more interference in picture naming than high-frequency words (i.e., distractor frequency effect; Miozzo & Caramazza, 2003). According to the response exclusion hypothesis, this effect has its origin at a postlexical stage and is related to a response buffer. The account predicts that the distractor frequency effect should only be present when a response to the word enters the response buffer. This was tested by masking the distractor (Experiment 2) and by presenting it at various time points before stimulus onset (Experiment 3). Results supported the hypothesis by showing that the effect was only present when distractors were visible, and if they were presented in close proximity to the target picture. These results have implications for the models of lexical access and for the tasks that can be used to study this process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Laboratory studies of antipredator behavior in the Mongolian gerbil (Meriones unguiculatus): factors affecting response attenuation with repeated presentations

A series of experiments was conducted to study the properties of the attenuation of responding to repeated presentation of overhead visual transients in the gerbil (Meriones unguiculatus). Results suggest that this attenuation consists of habituation to the repeated association of a potentially threatening sensory stimulus with an increasingly familiar spatial context. The results of these experiments further suggest that the likelihood of eliciting fleeing is a conjoint function of the degree of risk posed by an overhead sensory transient and the degree of safety that is to be gained by fleeing. Results are discussed in the context of the ecology of predator recognition and the structural organization of the rodent visual system.     

Temporal-order discrimination for selected auditory and visual stimulus dimensions

Thresholds for the discrimination of temporal order were determined for selected auditory and visual stimulus dimensions in 10 normal-adult volunteers. Auditory stimuli consisted of binary pure tones varying in frequency or sound pressure level, and visual stimuli consisted of binary geometric forms varying in size, orientation, or color. We determined the effect of psychophysical method and the reliability of performance across stimulus dimensions. Using a single-track adaptive procedure, Experiment 1 showed that temporal-order thresholds (TOTs) varied with stimulus dimension, being lowest for auditory frequency, intermediate for size, orientation, and auditory level, and longest for color. Test performance improved over sessions and the profile of thresholds across stimulus dimensions had a modest reliability. Experiment 2 used a double-interleaved adaptive procedure and TOTs were similarly ordered as in Experiment 1. However, TOTs were significantly lower for initially ascending versus descending tracks. With this method, the reliability of the profile across stimulus dimensions and tracks was relatively low. In Experiment 3, psychometric functions were obtained for each of the stimulus dimensions and thresholds were defined as the interpolated 70.7% correct point. The relative ordering of TOTs was similar to those obtained in the first two experiments. Non-monotonicities were found in some of the psychometric functions, with the most prominent being for the color dimension. A cross-experiment comparison of results demonstrates that TOTs and their reliability are significantly influenced by the psychophysical method. Taken together, these results support the notion that the temporal resolution of ordered stimuli involves perceptual mechanisms specific to a given sensory modality or submodality.     

Acute alcohol intoxication disrupts brightness but not olfactory conditioning in preweanling rats.

The present experiments tested the effect of acute alcohol administration on Pavlovian conditioning of 21-day-old rats using conditioned stimuli of two different sensory modalities—olfaction, an early developing sensory capacity functional at birth, and vision, a later developing sensory system not becoming functional until approximately 15 days of age. Conditioning and testing were conducted between 30 and 60 min following gastric intubation with either physiological saline or a mildly intoxicating alcohol dose (1.5 g/kg body weight). Brain alcohol levels were observed to remain at a peak and stable concentration during this period (Experiment 1). Alcohol impaired acquisition or expression of conditioned aversions to a visual cue paired with footshock when presented either as a single-element conditioned stimulus or as part of an odor/visual compound stimulus (Experiment 2), but it had no discernible effect on conditioned aversions to an olfactory stimulus that had similarly been paired with footshock (Experiments 2 and 3). The results suggest that alcohol may impair some aspects of learning but spare others, depending perhaps on the particular sensory modality to be conditioned. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dominance of global visual properties at birth.

Six experiments are reported that were aimed at demonstrating the presence in newborns of a perceptual dominance of global over local visual information in hierarchical patterns, similar to that observed in adults (D. Navon, 1977, 1981). The first four experiments showed that, even though both levels of visual information were detectable by the newborn (Experiments 1A and 1B), global cues enjoyed some advantage over local cues (Experiments 2 and 3). Experiments 4A and 4B demonstrated that the global bias was strictly dependent on the low spatial frequency content of the stimuli and vanished after selective removal of low spatial frequencies. The results are interpreted as suggesting parallels between newborns' visual processing and processing later in development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Faces are "spatial"--holistic face perception is supported by low spatial frequencies.

Faces are perceived holistically, a phenomenon best illustrated when the processing of a face feature is affected by the other features. Here, the authors tested the hypothesis that the holistic perception of a face mainly relies on its low spatial frequencies. Holistic face perception was tested in two classical paradigms: the whole-part advantage (Experiment 1) and the composite face effect (Experiments 2-4). Holistic effects were equally large or larger for low-pass filtered faces as compared to full-spectrum faces and significantly larger than for high-pass filtered faces. The disproportionate composite effect found for low-pass filtered faces was not observed when holistic perception was disrupted by inversion (Experiment 3). Experiment 4 showed that the composite face effect was enhanced only for low spatial frequencies, but not for intermediate spatial frequencies known be critical for face recognition. These findings indicate that holistic face perception is largely supported by low spatial frequencies. They also suggest that holistic processing precedes the analysis of local features during face perception. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Recognition memory and resource allocation as revealed by children's event-related potential responses to happy and angry faces.

Event-related potentials were used to examine the recognition of happy and angry faces by 4- to 6-year-old children. In 2 experiments, Ss viewed 100-ms presentations of a happy face and an angry face posed by a single model. The frequency with which these expressions were presented varied across experiments, and which face served as the target or nontarget stimulus varied within experiments. In Experiment 1, an early negative component (N400) was observed that distinguished between the 2 expressions, and a 2nd, later positive component (P700) was observed that distinguished between target and nontarget events. In Experiment 2, these components were again observed, although both now distinguished only between low- and high-probability events. Both were absent at posterior scalp, were most prominent at parietal and central scalp, and were minimal at frontal scalp. These results are discussed in the context of children's allocation of attentional and memory resources for briefly presented affective stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibitory mechanisms of attentional networks: Spatial and semantic inhibitory processing.

Four experiments assessed the relationships between the orienting and the executive networks of visual attention. Experiment 1 showed spatial inhibition of return (IOR) with target words. Experiment 2 showed a type of semantic inhibition that mimicked spatial IOR. Reaction times to targets preceded by 2 consecutively presented words, the prime and the intervening stimulus, were longer when the target and prime were related than when they were unrelated. Experiment 3 combined spatial and semantic inhibition in a lexical-decision task. Spatial IOR was observed with both related and unrelated targets, but semantic inhibition was observed only when target words were presented in uncued locations. A similar interaction between IOR and positive semantic priming was observed when the intervening stimulus was not presented (Experiment 4). Implications for the relationships between the 2 attentional networks are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory preference and overselective responding in autistic children

Five autistic and five normal children were allowed to register a sensory modality preference by bar pressing to select either a visual (slides) or an auditory (music) stimulus. The children were then taught a discrimination between the presence or absence of a compound auditory-visual stimulus (white noise and light). Testing for stimulus overselectivity revealed that the autistic children attended to only one aspect of the compound stimulus. In all cases this was the sensory modality that was selected during the preference test. Significant correlations were obtained between Gesell developmental scores and degree of overselectivity. Normal children registered an equal preference for music and slides and displayed no overselectivity.     

Loudness change in response to dynamic acoustic intensity.

Three experiments investigate psychological, methodological, and domain-specific characteristics of loudness change in response to sounds that continuously increase in intensity (up-ramps), relative to sounds that decrease (down-ramps). Timbre (vowel, violin), layer (monotone, chord), and duration (1.8 s, 3.6 s) were manipulated in Experiment 1. Participants judged global loudness change between pairs of spectrally identical up-ramps and down-ramps. It was hypothesized that loudness change is overestimated in up-ramps, relative to down-ramps, using simple speech and musical stimuli. The hypothesis was supported and the proportion of up-ramp overestimation increased with stimulus duration. Experiment 2 investigated recency and a bias for end-levels by presenting paired dynamic stimuli with equivalent end-levels and steady-state controls. Experiment 3 used single stimulus presentations, removing artifacts associated with paired stimuli. Perceptual overestimation of loudness change is influenced by (1) intensity region of the dynamic stimulus; (2) differences in stimulus end-level; (3) order in which paired items are presented; and (4) duration of each item. When methodological artifacts are controlled, overestimation of loudness change in response to up-ramps remains. The relative influence of cognitive and sensory mechanisms is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency effects in spoken and visual word recognition: Evidence from dual-task methodologies.

The authors report 3 dual-task experiments concerning the locus of frequency effects in word recognition. In all experiments, Task 1 entailed a simple perceptual choice and Task 2 involved lexical decision. In Experiment 1, an underadditive effect of word frequency arose for spoken words. Experiment 2 also showed underadditivity for visual lexical decision. It was concluded that word frequency exerts an influence prior to any dual-task bottleneck. A related finding in similar dual-task experiments is Task 2 response postponement at short stimulus onset asynchronies. This was explored in Experiment 3, and it was shown that response postponement was equivalent for both spoken and visual word recognition. These results imply that frequency-sensitive processes operate early and automatically. (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)