Thurstone's discriminal processes fifty years later

Four issues are discussed concerning Thurstone's discriminal processes: the distributions governing the representation, the nature of the response decision rules, the relation of the mean representation to physical characteristics of the stimulus, and factors affecting the variance of the representation. A neural schema underlying the representation is proposed which involves samples in time of pulse trains on individual neural fibers, estimators of parameters of the several pulse trains, samples of neural fibers, and an aggregation of the estimates over the sample. The resulting aggregated estimate is the Thurstonian representation. Two estimators of pulse rate, which is monotonic with signal intensity, are timing and counting ratios and two methods of aggregation are averaging and maximizing. These lead to very different predictions in a speed-accuracy experiment; data indicate that both estimators are available and the aggregation is by averaging. Magnitude estimation data are then used both to illustrate an unusual response rule and to study the psychophysical law. In addition, the pattern of variability and correlation of magnitude estimates on successive trials is interpreted in terms of the sample size over which the aggregation takes place. Neural sample size is equated with selective attention, and is an important factor affecting the variability of the representation. It accounts for the magical number seven phenomenon in absolute identification and predicts the impact of nonuniform distributions of intensities on the absolute identification of two frequencies. 1977 Psychometric Society Presidential Address. This work was supported in part by a grant of the National Science Foundation to Harvard University. I wish to express my appreciation to S. Burbeck, D. M. Green, M. Shaw, and B. Wandell for their useful comments on an earlier draft of this paper.     

The relationship between auditory temporal processing,phonemic awareness,and reading disability

Recent research suggests an auditory temporal deficit as a possible contributing factor to poor phonemic awareness skills. This study investigated the relationship between auditory temporal processing of nonspeech sounds and phonological awareness ability in children with a reading disability, aged 8-12 years, using Tallal's tone-order judgement task. Normal performance on the tone-order task was established for 36 normal readers. Forty-two children with developmental reading disability were then subdivided by their performance on the tone-order task. Average and poor tone-order subgroups were then compared on their ability to process speech sounds and visual symbols, and on phonological awareness and reading. The presence of a tone-order deficit did not relate to performance on the order processing of speech sounds, to poorer phonological awareness or to more severe reading difficulties. In particular, there was no evidence of a group by interstimulus interval interaction, as previously described in the literature, and thus little support for a general auditory temporal processing difficulty as an underlying problem in poor readers. In this study, deficient order judgement on a nonverbal auditory temporal order task (tone task) did not underlie phonological awareness or reading difficulties.     

Discrimination of faces and houses by rhesus monkeys: the role of stimulus expertise and rotation angle

The face inversion effect, or impaired recognition of upside down compared to upright faces, is used as a marker for the configural processing of faces in primates. The inversion effect in humans and chimpanzees is strongest for categories of stimuli for which subjects have considerable expertise, primarily conspecifics’ faces. Moreover, discrimination performance decreases linearly as faces are incrementally rotated from upright to inverted. This suggests that rotated faces must be transformed, or normalized back into their most typical viewpoint before configural processing can ensue, and the greater the required normalization, the greater the likelihood of errors resulting. Previous studies in our lab have demonstrated a general face inversion effect in rhesus monkeys that was not influenced by expertise. Therefore, the present study examined the influence of rotation angle on the visual perception of face and nonface stimuli that varied in their level of expertise to further delineate the processes underlying the inversion effect in rhesus monkeys. Five subjects discriminated images in five orientation angles. Results showed significant linear impairments for all stimulus categories, including houses. However, compared to the upright images, only rhesus faces resulted in worse performance at rotation angles greater than 45°, suggesting stronger configural processing for stimuli for which subjects had the greatest expertise.     

Attention to attention in domestic dog (Canis familiaris) dyadic play

The social cognitive capacities of dogs, including their communication skills and use of visual attention cues, have recently been investigated in numerous experimental studies. This paper reports on research of domestic dog behavior in a natural setting, which shows sensitivity to the visual attention of their partners when engaged in dyadic rough-and-tumble play. The sequential behaviors and head-direction of both dogs were noted throughout the bouts. The behaviors were differentially used according to the partner’s posture. Play signals were sent nearly exclusively to forward-facing conspecifics; attention-getting behaviors were used most often when a playmate was facing away, and before signaling an interest to play. In addition, the mode of attention-getter matched the degree of inattentiveness of the playmate: stronger attention-getters were used when a playmate was looking away or distracted, less forceful ones when the partner was facing forward or laterally. In other words, these dogs showed attention to, and acted to manipulate, a feature of other dogs that mediates their ability to respond: which feature in human interaction is called “attention”.

物理线索缺失下的错误记忆

本研究采用基于语义关联的DRM范式,通过改变测试词语的字体来探究语义痕迹和物理线索对错误记忆的影响。结果表明,语义关联产生的要义痕迹依然是错误记忆产生的重要因素,而对物理线索的操作则使真实记忆和错误记忆发生了分离,在字体改变的条件下,被试的错误记忆更加严重。     

学习不良儿童的元认知偏差：内部线索的影响

通过改变实验材料内部线索,旨在考察内部线索在学习不良儿童元认知偏差形成过程中的影响。实验1发现,学习不良儿童低关联字对的元认知偏差显著高于一般儿童,关联强度对学习判断的影响显著小于对测试成绩的影响;实验2发现,学习不良儿童反向方向字对的元认知偏差显著高于一般儿童,关联方向对学习判断的影响显著小于对测试成绩的影响。综合以上研究发现,相对一般儿童,学习不良儿童存在更大的元认知偏差,内部线索对学习判断和测试成绩的影响不一致模式适用于两组儿童。     

线索的数量和联接性对返回抑制的影响

使用联接和离散的线索呈现方式比较了注意的易化效应和返回抑制的效果。实验一同时线索化3个外周位置,实验二同时线索化5个外周位置。结果表明：（1）在同时线索化3个位置的情境下,联接和离散这两种线索化方式均能产生返回抑制;（2）在同时线索化5个位置的情境下,联接条件仍能产生抑制效应,而离散条件没有产生。结果说明联接的方式让多个位置的线索被理解为一个线索,提示注意有“沿着物体弥散”的性质。     

Effects of cocaine on simple reaction times and sensory thresholds in baboons.

The effects of chronic, daily administration of cocaine on auditory and visual reaction times and thresholds were studied in baboons. Single intramuscular injections of cocaine hydrochloride (0.1 to 5.6 mg/kg) were given once daily for periods of 10 to 25 days, and were followed immediately by psychophysical tests designed to assess cocaine's effects on simple reaction times as on auditory and visual threshold functions. Consistent reductions in reaction times were frequently observed over the cocaine dose range of 0.32 to 1.0 mg/kg; at higher doses, either decreases or increases in reaction times were observed, depending upon the animal. Lowered reaction times generally occurred immediately following the 1st day's cocaine injection, and continued through all subsequent days during the dose administration period, suggesting little development of tolerance or sensitivity to these reaction-time effects. Reaction-time decreases showed a U-shaped dose-effect function. The greatest decreases in reaction times occurred from 0.32 to 1.0 mg/kg, and produced an average reaction-time decrease of 10 to 12%. Concurrently measured auditory and visual thresholds showed no systematic changes as a function of cocaine dose. Pausing was observed during performance of the psychophysical tasks, with the length of total session pause times being directly related to cocaine dose.     

Nonverbal emotion displays, communication modality, and the judgment of personality

The goal of this research was to investigate the impact of nonverbal expressive cues on the attribution of the Big Five personality traits. Expressive cues of fear, disgust, happiness, and sadness were elicited in a sample of 22 encoders while watching films, narrating, and posing. Encoders’ personalities were rated by themselves and unacquainted raters who watched the encoders, and blind judges rated the traits of a typical student. Expressive cues influenced the raters’ attribution of personality, but this influence was weakest when the encoders expressed happiness (vs. negative emotions) and when they were narrating an emotional experience (when the cues were least potent). Negative and strong expressive cues interfered with the application of a normative, and more accurate, judgment strategy.     

What’s in a name? Subliminally activating trusting behavior

Because the choice to trust is inherently risky, people naturally assess others’ trustworthiness before they engage in trusting actions. The research reported here suggests that the trust development process may start before the conscious assessment of trustworthiness, via the activation of a relational schema. We present three experiments that examined the automatic, non-conscious activation of interpersonal trusting behavior via a variety of subliminal cues: positive or negative, relational or non-relational, and trust-related or not. In all three studies, subliminal relational cues influenced subsequent trusting behavior, apparently without conscious awareness. Results from the third study also indicated that subliminal relational cues that were specifically trust-related influenced trustors’ expectations of the likelihood of reciprocity. Overall, the data provide initial evidence that the development of interpersonal trust can start before and beneath conscious awareness.