Category similarity affects study choices in self-regulated learning.

During learning, interleaving exemplars from different categories (e.g., ABCBCACAB) rather than blocking by category (e.g., AAABBBCCC) often enhances inductive learning, especially when the categories are highly similar. However, when allowed to select their own study schedules, learners overwhelmingly tend to block rather than interleave. Category similarity has been shown to moderate the relative benefit of interleaved versus blocked study. We investigated whether learners were sensitive to category similarity when choosing exemplars for study, and whether these choices predicted their learning outcomes. In Experiment 1, learners interleaved more often when the categories were highly similar (difficult to discriminate from each other), compared with when similarity was low. In Experiment 2, learners were presented with two sets of categories to learn; categories within each set were similar to each other, but categories were dissimilar across sets. When learners chose to interleave, they tended to switch to a similar rather than dissimilar category. Importantly, learners' study choices predicted their subsequent categorization performance. Our findings suggest that learners are strategic in their search for commonalities within versus differences among categories and can regulate their study behaviors based on category similarity.

Flicker-Induced Time Dilation Does Not Modulate EEG Correlates of Temporal Encoding.

In this study, we used EEG to investigate how visual stimulus dynamics (i.e. flicker) affect the mechanisms of duration perception. Previous studies have demonstrated that flickering visual stimuli are judged longer than equally long non-flickering stimuli. We tested whether this effect of flicker on duration judgments is mediated by changes in temporal encoding during the time interval. Here, temporal encoding refers to the perception of the unfolding of time throughout the temporal interval, also termed the "clock stage" in information processing models of interval timing. We hypothesized that if flicker mediates duration perception by affecting temporal encoding, then the dilation-effect should be reflected by neural correlates of temporal encoding. We presented flickering and steady stimuli in a duration bisection task and found that flicker dilated perceived duration. The EEG analysis allowed us to isolate a putative neural correlate of temporal encoding: a modulation of the amplitude of the contingent negative variation (CNV) by stimuli classified as "long" compared to physically identical stimuli classified as "short". However, flicker did not affect the CNV amplitude, suggesting that flicker does not dilate perceived duration by affecting temporal encoding. Possibly, flicker might affect only later stages of temporal processing such as interval comparison or decision making.

Probing interval timing with scalp-recorded electroencephalography (EEG).

Humans, and other animals, are able to easily learn the durations of events and the temporal relationships among them in spite of the absence of a dedicated sensory organ for time. This chapter summarizes the investigation of timing and time perception using scalp-recorded electroencephalography (EEG), a non-invasive technique that measures brain electrical potentials on a millisecond time scale. Over the past several decades, much has been learned about interval timing through the examination of the characteristic features of averaged EEG signals (i.e., event-related potentials, ERPs) elicited in timing paradigms. For example, the mismatch negativity (MMN) and omission potential (OP) have been used to study implicit and explicit timing, respectively, the P300 has been used to investigate temporal memory updating, and the contingent negative variation (CNV) has been used as an index of temporal decision making. In sum, EEG measures provide biomarkers of temporal processing that allow researchers to probe the cognitive and neural substrates underlying time perception.

The functional role of the frontal cortex in pre-attentive auditory change detection.

Accounts of the functional role of the frontal cortex in pre-attentive auditory change detection include attention switching, response inhibition, contrast enhancement, and activation of a predictive model. These accounts assume different sequential activation patterns between the temporal and frontal cortices: Change detection in the auditory areas of the superior temporal cortex (STC) followed by inferior frontal cortex (IFC) activation for attention switching and response inhibition; STC preceded by IFC activation for contrast enhancement; and an IFC-STC-IFC activation sequence for the predictive model. We used the event-related optical signal (EROS), which provides a temporal resolution of milliseconds and a spatial resolution of 5 to 10mm, combined with lagged correlation path modeling to examine the response of the right frontal and temporal cortices to auditory duration deviants of varying magnitude. Event-related potentials (ERPs) were also recorded, as was the slow optical (hemodynamic) brain response. The data analyses revealed temporal-frontal, frontal-temporal-frontal, and temporal-frontal activation patterns when the deviants represented relatively large, medium, and small changes from the standard stimulus, respectively. These results indicate that the degree of deviance modulates spatio-temporal dynamics within the STC-IFC auditory change detection network.

Perceptual and conceptual priming of environmental sounds.

It is still unknown whether sonic environments influence the processing of individual sounds in a similar way as discourse or sentence context influences the processing of individual words. One obstacle to answering this question has been the failure to dissociate perceptual (i.e., how similar are sonic environment and target sound?) and conceptual (i.e., how related are sonic environment and target?) priming effects. In this study, we dissociate these effects by creating prime-target pairs with a purely perceptual or both a perceptual and conceptual relationship. Perceptual prime-target pairs were derived from perceptual-conceptual pairs (i.e., meaningful environmental sounds) by shuffling the spectral composition of primes and targets so as to preserve their perceptual relationship while making them unrecognizable. Hearing both original and shuffled targets elicited a more positive N1/P2 complex in the ERP when targets were related to a preceding prime as compared with unrelated. Only related original targets reduced the N400 amplitude. Related shuffled targets tended to decrease the amplitude of a late temporo-parietal positivity. Taken together, these effects indicate that sonic environments influence first the perceptual and then the conceptual processing of individual sounds. Moreover, the influence on conceptual processing is comparable to the influence linguistic context has on the processing of individual words.

3D Hand-Motion Tracking and Bottom-Up Classification Sheds Light on the Physical Properties of Gentle Stroking.

Despite much research on the perception of gentle stroking, its motion characteristics and modulation by social intent remain largely unknown. Here we addressed this situation by asking volunteers to gently stroke a dog, the arm of their romantic partner, their own arm, or a foam arm in a pleasant manner, as if to provide comfort, or as fast/slow as possible. Stroking motion was tracked with a sensor attached to the back of the hand and processed using MPAL, a new 3D motion analysis tool. Statistical testing was both hypothesis-driven and exploratory. Hypothesis-driven tests revealed comparable stroking velocities for social (dog, partner) and non-social touch targets, but an overall slower velocity for pleasant and slow as compared with fast stroking. Additionally, stroking a social target or with a pleasant intent entailed less motion along the target's front/back axis, increased motion along the left/right axis and increased temporal variability between main strokes. An exploratory linear discriminant analysis on 26 motion features revealed that stroking a social target was more distinct than stroking in a pleasant manner and that the former, and to a lesser extent the latter, were strongly associated with features indexing spatio-temporal variability. Thus, touchers socially tune their stroking motion by reducing its predictability, which may make the touchee's experiences more pleasurable by facilitating the differentiation between self- and other touch. Together, our results offer useful directions for future research on gentle stroking and emphasize the need to consider the natural physical properties of touch.

Cortico-striatal representation of time in animals and humans.

Interval timing in the seconds-to-minutes range is crucial to learning, memory, and decision-making. Recent findings argue for the involvement of cortico-striatal circuits that are optimized by the dopaminergic modulation of oscillatory activity and lateral connectivity at the level of cortico-striatal inputs. Striatal medium spiny neurons are proposed to detect the coincident activity of specific beat patterns of cortical oscillations, thereby permitting the discrimination of supra-second durations based upon the reoccurring patterns of subsecond neural firing. This proposal for the cortico-striatal representation of time is consistent with the observed psychophysical properties of interval timing (e.g. linear time scale and scalar variance) as well as much of the available pharmacological, lesion, patient, electrophysiological, and neuroimaging data from animals and humans (e.g. dopamine-related timing deficits in Huntington's and Parkinson's disease as well as related animal models). The conclusion is that although the striatum serves as a 'core timer', it is part of a distributed timing system involving the coordination of large-scale oscillatory networks.

Angry, old, male - and trustworthy? How expressive and person voice characteristics shape listener trust.

This study examined how trustworthiness impressions depend on vocal expressive and person characteristics and how their dependence may be explained by acoustical profiles. Sentences spoken in a range of emotional and conversational expressions by 20 speakers differing in age and sex were presented to 80 age and sex matched listeners who rated speaker trustworthiness. Positive speaker valence but not arousal consistently predicted greater perceived trustworthiness. Additionally, voices from younger as compared with older and female as compared with male speakers were judged more trustworthy. Acoustic analysis highlighted several parameters as relevant for being perceived as trustworthy (i.e., accelerated tempo, low harmonic-to-noise ratio, more shimmer, low fundamental frequency, more jitter, large intensity range) and showed that effects partially overlapped with those for perceived speaker affect, age, but not sex. Specifically, a fast speech rate and a lower harmonic-to-noise ratio differentiated trustworthy from untrustworthy, positive from negative, and younger from older voices. Male and female voices differed in other ways. Together, these results show that a speaker's expressive as well as person characteristics shape trustworthiness impressions and that their effect likely results from a combination of low-level perceptual and higher-order conceptual processes.

Rhythmic timing in aging adults: On the role of cognitive functioning and structural brain integrity.

Here we asked whether impaired timing in older adults results from an aging clock or a more general brain and cognitive decline. Healthy aging adults (N = 70, aged 62-83 years) tapped to the beat of a periodic and a syncopated rhythm. Analyses focused on performance differences between rhythms (periodic-syncopated), which reduced the impact of timing unrelated processes. Apart from tapping, participants completed a cognitive assessment and neuroimaging of gray matter volume (GMV) and fractional anisotropy (FA) globally as well as regionally (cortical: auditory, premotor, paracentral; subcortical: putamen, caudate, cerebellum). The rhythm difference showed no significant age effects for tapping asynchrony and an age-related decrease for tapping consistency. Additionally, age reduced cognitive functioning, global GMV/FA, and, beyond this, auditory GMV. Irrespective of age, the rhythm difference in tapping asynchrony was linked, not to GMV, but to caudal, premotor, and paracentral FA after controlling for global FA. Tapping consistency was associated with global rather than regional brain integrity. Additionally, age differences in tapping consistency were mediated by a decline in global brain integrity as well as cognitive functioning. Together these results agree with previous proposals differentiating between timing accuracy and reliability and suggest that aging largely preserves the former but not the latter. Whereas timing accuracy may depend on an internal clock supported by robust striatocortical circuitry, timing reliability may depend on global brain and cognitive functioning, which show a pronounced age-related decline. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Perception of tone and aspiration contrasts in Chinese children with dyslexia.

BACKGROUND: Previous research has shown a relationship between speech perception and dyslexia in alphabetic writing. In these studies speech perception was measured using phonemes, a prominent feature of alphabetic languages. Given the primary importance of lexical tone in Chinese language processing, we tested the extent to which lexical tone and aspiration, two fundamental dimensions of Cantonese speech not represented in writing, would distinguish dyslexic from non-dyslexic 8-year-old Chinese children. Tone and aspiration were tested in addition to other phonological processing skills across groups to determine the importance of different aspects of phonological sensitivity in relation to reading disability. METHODS: Dyslexic children and age-matched and reading-level controls were tested on their categorical perception of minimal pairs contrasting in tone and aspiration, phonological awareness, rapid digit naming, and Chinese reading abilities. RESULTS: While performing similarly to reading-level controls, dyslexic children perceived tone and aspiration contrasts less categorically and accurately than age-matched controls. They also performed more poorly than the age-matched controls on rapid digit naming and a measure of phonological awareness testing children's sensitivity to different grain size units. CONCLUSIONS: Dyslexia in non-alphabetic Chinese correlates with the categorical organization and accuracy of Cantonese speech perception, along the tone and aspiration dimensions. This association with reading is mediated by its association with phonological awareness. Therefore, dyslexia is universally at least partly a function of basic speech and phonological processes independent of whether the speech dimensions in question are coded in writing.

Angry, old, male - and trustworthy? How expressive and person voice characteristics shape listener trust.

This study examined how trustworthiness impressions depend on vocal expressive and person characteristics and how their dependence may be explained by acoustical profiles. Sentences spoken in a range of emotional and conversational expressions by 20 speakers differing in age and sex were presented to 80 age and sex matched listeners who rated speaker trustworthiness. Positive speaker valence but not arousal consistently predicted greater perceived trustworthiness. Additionally, voices from younger as compared with older and female as compared with male speakers were judged more trustworthy. Acoustic analysis highlighted several parameters as relevant for differentiating trustworthiness ratings and showed that effects largely overlapped with those for speaker valence and age, but not sex. Specifically, a fast speech rate, a low harmonic-to-noise ratio, and a low fundamental frequency mean and standard deviation differentiated trustworthy from untrustworthy, positive from negative, and younger from older voices. Male and female voices differed in other ways. Together, these results show that a speaker's expressive as well as person characteristics shape trustworthiness impressions and that their effect likely results from a combination of low-level perceptual and higher-order conceptual processes.

Vocal threat enhances visual perception as a function of attention and sex.

This pre-registered event-related potential study explored how vocal emotions shape visual perception as a function of attention and listener sex. Visual task displays occurred in silence or with a neutral or an angry voice. Voices were task-irrelevant in a single-task block, but had to be categorized by speaker sex in a dual-task block. In the single task, angry voices increased the occipital N2 component relative to neutral voices in women, but not men. In the dual task, angry voices relative to neutral voices increased occipital N1 and N2 components, as well as accuracy, in women and marginally decreased accuracy in men. Thus, in women, vocal anger produced a strong, multifaceted visual enhancement comprising attention-dependent and attention-independent processes, whereas in men, it produced a small, behavior-focused visual processing impairment that was strictly attention-dependent. In sum, these data indicate that attention and listener sex critically modulate whether and how vocal emotions shape visual perception.

Categorical scaling of duration bisection in pigeons (Columba livia), mice (Mus musculus), and humans (Homo sapiens).

A fundamental assumption underlying research in translational neuroscience is that animal models represent many of the same neurocognitive mechanisms and decision processes used by humans. Clear demonstrations of such correspondences will be crucial to the discovery of the neurobiological underpinnings of higher-level cognition. One domain likely to support fruitful comparisons is interval timing, because humans and other animals appear to share basic similarities in their ability to discriminate the durations of events in the seconds-to-minutes range. Here, we report that in a duration-bisection procedure using a series of anchor durations ranging from 2 through 5 s, pigeon, mouse, and human subjects classified a given signal duration as subjectively shorter than an adjacent, physically shorter signal duration when the two durations lay on opposite sides of a putative category boundary. These bisection reversals provide strong evidence for continuity of temporal cognition across a wide range of vertebrate species.

Prenatal-choline supplementation differentially modulates timing of auditory and visual stimuli in aged rats.

Choline supplementation of the maternal diet has a long-term facilitative effect on the interval-timing ability and temporal memory of the offspring. Here, we examined whether prenatal-choline supplementation has modality-specific effects on duration discrimination in aged (20 mo) male rats. Adult offspring of rats that were given sufficient choline in their chow (CON: 1.1 g/kg) or supplemental choline added to their drinking water (SUP: 3.5 g/kg) during embryonic days (ED) 12-17 were trained and tested on a two-modality (auditory and visual signals) duration bisection procedure (2 s vs. 8 s). Intensity (high vs. low) of the auditory and visual timing signals was systematically manipulated across test sessions such that all combinations of signal intensity by modality were tested. Psychometric response functions indicated that prenatal-choline supplementation systematically increased sensitivity to auditory signals relative to visual signals, thereby magnifying the modality effect that sounds are judged to be longer than lights of equivalent duration. In addition, sensitivity to signal duration was greater in rats given prenatal-choline supplementation, particularly at low intensities of both the auditory and visual signals. Overall, these results suggest that prenatal-choline supplementation impacts interval timing by enhancing the differences in temporal integration between auditory and visual stimuli in aged subjects.

Sensory modality and time perception in children and adults.

This experiment investigated the effect of signal modality on time perception in 5- and 8-year-old children as well as young adults using a duration bisection task in which auditory and visual signals were presented in the same test session and shared common anchor durations. Durations were judged shorter for visual than for auditory signals by all age groups. However, the magnitude of this modality difference was larger in the children than in the adults. Sensitivity to time was also observed to increase with age for both modalities. Taken together, these two observations suggest that the greater modality effect on duration judgments for the children, for whom attentional abilities are considered limited, is the result of visual signals requiring more attentional resources than are needed for the processing of auditory signals. Within the framework of the information-processing model of Scalar Timing Theory, these effects are consistent with a developmental difference in the operation of the "attentional switch" used to transfer pulses from the pacemaker into the accumulator. Specifically, although timing is more automatic for auditory than visual signals in both children and young adults, children have greater difficulty in keeping the switch in the closed state during the timing of visual signals.

Preattentive change detection using the event-related optical signal.

The current study revealed right STG activation followed by IFG activation in response to temporal deviant events. The sequence and general time course of the activation pattern replicates our earlier findings for omission deviants, but with an SOA that was an order of magnitude larger. It also extends the findings to include early deviants, and thereby it strengthens claims about the spatial localization of the deviance response and the functional roles the STG and the IFG play in that response. Finally, the IFG activity elicited by the early deviants that preceded the STG activity suggests the IFG may play a dual role in preattentive change detection. Future EROS studies using parametric modulations of deviance magnitude will help to provide more information about the functional role of IFG in preattentive change detection.

Separate requirements for detection and perceptual stability of motion in interocular suppression.

In interocular masking, a stimulus presented to one eye (the mask) is made stronger in order to suppress from awareness the target stimulus presented to the other eye. We investigated whether matching the features of the target and the mask would lead to more effective suppression (feature-selective suppression), or not (i.e., non-selective suppression). To control the temporal characteristics of the stimuli, we used a dynamic interocular mask to suppress a moving target, and found that neither matching speed nor pattern of motion led to more effective suppression. Instead, a faster target was detected faster, regardless of the mask type or speed, while a relatively slow (about 1°/s) mask was more perceptually stable (i.e., maintained suppression longer) in a non-selective fashion. While the requirement for target detectability, i.e., salience, is well characterized, relatively little attention is given to the factors that make a mask percept more perceptually stable. Based on these results, we argue that there are separate requirements for detection and perceptual stability.

Familiarity Detection is an Intrinsic Property of Cortical Microcircuits with Bidirectional Synaptic Plasticity.

Humans instantly recognize a previously seen face as "familiar." To deepen our understanding of familiarity-novelty detection, we simulated biologically plausible neural network models of generic cortical microcircuits consisting of spiking neurons with random recurrent synaptic connections. NMDA receptor (NMDAR)-dependent synaptic plasticity was implemented to allow for unsupervised learning and bidirectional modifications. Network spiking activity evoked by sensory inputs consisting of face images altered synaptic efficacy, which resulted in the network responding more strongly to a previously seen face than a novel face. Network size determined how many faces could be accurately recognized as familiar. When the simulated model became sufficiently complex in structure, multiple familiarity traces could be retained in the same network by forming partially-overlapping subnetworks that differ slightly from each other, thereby resulting in a high storage capacity. Fisher's discriminant analysis was applied to identify critical neurons whose spiking activity predicted familiar input patterns. Intriguingly, as sensory exposure was prolonged, the selected critical neurons tended to appear at deeper layers of the network model, suggesting recruitment of additional circuits in the network for incremental information storage. We conclude that generic cortical microcircuits with bidirectional synaptic plasticity have an intrinsic ability to detect familiar inputs. This ability does not require a specialized wiring diagram or supervision and can therefore be expected to emerge naturally in developing cortical circuits.

Spread spectrum time-resolved diffuse optical measurement system for enhanced sensitivity in detecting human brain activity.

Diffuse optical spectroscopy (DOS) and imaging methods have been widely applied to noninvasive detection of brain activity. We have designed and implemented a low cost, portable, real-time one-channel time-resolved DOS system for neuroscience studies. Phantom experiments were carried out to test the performance of the system. We further conducted preliminary human experiments and demonstrated that enhanced sensitivity in detecting neural activity in the cortex could be achieved by the use of late arriving photons.

Task and sex modulate the brain response to emotional incongruity in Asian listeners.

In order to recognize banter or sarcasm in social interactions, listeners must integrate verbal and vocal emotional expressions. Here, we investigated event-related potential correlates of this integration in Asian listeners. We presented emotional words spoken with congruous or incongruous emotional prosody. When listeners classified word meaning as positive or negative and ignored prosody, incongruous trials elicited a larger late positivity than congruous trials in women but not in men. Sex differences were absent when listeners evaluated the congruence between word meaning and emotional prosody. The similarity of these results to those obtained in Western listeners suggests that sex differences in emotional speech processing depend on attentional focus and may reflect culturally independent mechanisms.