Do humans and baboons use the same information when categorizing human and baboon faces?

What information is used for sorting pictures of complex stimuli into categories? We applied a reverse correlation method to reveal the visual features mediating categorization in humans and baboons. Two baboons and 6 humans were trained to sort, by species, pictures of human and baboon faces on which random visual noise was superimposed. On ambiguous probe trials, a human-baboon morph was presented, eliciting "human" responses on some trials and "baboon" responses on others. The difference between the noise patterns that induced the two responses made explicit the information mediating the classification. Unlike the humans, the baboons based their categorization on information that closely matched that used by a theoretical observer responding solely on the basis of the pixel similarities between the probe and training images. We show that the classification-image technique and principal components analysis provide a method to make explicit the differences in the information mediating categorization in humans and animals.     

Visual object agnosia without prosopagnosia or alexia: Evidence for hierarchical theories of visual recognition

Abstract

A single case study is presented of a patient, Mr. W, with a selective deficit in recognizing pictures and real objects, linked to impaired stored visual knowledge about objects. Despite this, Mr. W maintained a preserved ability both to read aloud printed words and to recognize famous faces, when compared with age-matched control subjects. In addition, his access to semantic information from words was superior to that from pictures. The data provide evidence that visual agnosia can occur without alexia or prosopagnosia, contrary to recent proposals (Farah 1990, 1991). This finding is consistent with a hierarchical model of visual object recognition in which agnosia can reflect impaired stored knowledge of objects without accompanying perceptual deficits. The selective recognition deficit for objects further indicates that stored knowledge concerning different classes of visual stimuli (common objects, faces, and words) is separately represented in the brain.     

Rapid picture presentation and affective engagement

Emotional reactions were assessed to pictorial stimuli presented in a continuous stream at rapid speeds that compromise conceptual memory and the processing of specific picture content. Blocks of unpleasant, neutral, or pleasant pictures were presented at the rate of either three pictures per second or seven pictures per second. Even with rapid presentation rates, startle reflexes, corrugator muscle activity, and skin conductance responses were heightened when viewing unpleasant pictures. These effects were stronger later in the aversive block, suggesting that cumulative exposure increasingly activates the defense system. The findings suggest that, despite conceptual masking inherent in rapid serial visual presentation, affective pictures prompt measurable emotional engagement.     

Pupillary responses to pictures and descriptions of sex-stereotyped stimuli

An attempt was made to replicate Hess and Polt's (1960) report of sex differences in pupillary responses to sex-stereotyped pictures. Some methodological refinements were used that seem desirable for future studies. College men and women were either shown or told they would be shown pictures of a semi-nude man, a semi-nude woman, a baby, and a landscape. With resting pupil size as covariate, a three-factor analysis of covariance did not show sex differences in response to visually presented stimuli. Men responded more to verbal than visual mode of presentation and more than women to verbal stimuli. Contrary to previous results, men responded as much or more than women to verbal or visual presentation of baby stimuli. The verbal or anticipatory mode seems to be at least as sensitive as the visual and eliminates problems of control of visual materials.     

SuperLab: General-purpose Macintosh software for human experimental psychology and psychological testing

SuperLab is a general-purpose psychology testing package for the Macintosh. SuperLab presents static visual and auditory stimuli in blocks of trials, each trial consisting of a user-specified sequence of stimuli. Responses can be recorded from the keyboard or from switches connected to an I/O board. Stimuli can be contingent on subjects’ responses, allowing feedback based on response accuracy. Timing uses Time Manager routines from the Macintosh Toolbox. Data are recorded in a text format with tabs delimiting fields, allowing analysis and presentation by other Macintosh spreadsheet, statistics, and graph-making applications. SuperLab has a Macintosh user interface for developing experiments. Psychological tasks can also be designed and modified with any application that generates a text format file.     

The effect of ageing on the recollection of emotional and neutral pictures

This study investigated age-related differences in recognition memory for emotional and neutral pictures. Younger and older participants were asked to rate pictures according to their emotional valence, arousal, and visual complexity. Two weeks later they had to recognise these pictures and the states of awareness associated with memory were assessed with the "remember/know/guess" paradigm. We found that, although the influence of emotion on recognition accuracy (as assessed by d') was similar in both age groups, the tendency for positive and negative pictures to create a rich recollective experience was weaker in older adults. In addition, "remember" responses were more often based on a recollection of emotional reactions in older than in younger participants. We suggest that the elderly tend to focus on their feelings when confronted with emotional pictures, which could have impaired their memory for the contextual information associated with these stimuli.     

The effect of ageing on the recollection of emotional and neutral pictures

This study investigated age-related differences in recognition memory for emotional and neutral pictures. Younger and older participants were asked to rate pictures according to their emotional valence, arousal, and visual complexity. Two weeks later they had to recognise these pictures and the states of awareness associated with memory were assessed with the “remember/know/guess” paradigm. We found that, although the influence of emotion on recognition accuracy (as assessed by d′) was similar in both age groups, the tendency for positive and negative pictures to create a rich recollective experience was weaker in older adults. In addition, “remember” responses were more often based on a recollection of emotional reactions in older than in younger participants. We suggest that the elderly tend to focus on their feelings when confronted with emotional pictures, which could have impaired their memory for the contextual information associated with these stimuli.     

疼痛面孔注意加工中共情的作用——来自眼动的证据

疼痛的威胁警示与趋近救助冲突近来受到研究者的关注。本研究结合点探测范式与眼动技术,以疼痛面孔和中性面孔为实验材料,探讨共情在疼痛功能冲突中所扮演的角色。我们收集了33名被试的有效眼动数据,结果发现,与中性面孔相比,被试对疼痛面孔图片的早期注意定向更快（首次注视到达时间更短）、晚期注意维持更长（注视次数更多、总注视持续时间更长）;与低共情组相比,高共情组被试对面孔的总注视持续时间更长,分组分析显示只有髙共情组对疼痛面孔的总注视持续时间比中性面孔长。结果表明,被试存在疼痛面孔注意偏向,被试的共情水平可能作为一个调节变量影响其在注意维持阶段对疼痛威胁的知觉。     

Recognition memory strength is predicted by pupillary responses at encoding while fixation patterns distinguish recollection from familiarity

Thirty-five healthy participants incidentally encoded a set of man-made and natural object pictures, while their pupil response and eye movements were recorded. At retrieval, studied and new stimuli were rated as novel, familiar (strong, moderate, or weak), or recollected. We found that both pupil response and fixation patterns at encoding predict later recognition memory strength. The extent of pupillary response accompanying incidental encoding was found to be predictive of subsequent memory. In addition, the number of fixations was also predictive of later recognition memory strength, suggesting that the accumulation of greater visual detail, even for single objects, is critical for the creation of a strong memory. Moreover, fixation patterns at encoding distinguished between recollection and familiarity at retrieval, with more dispersed fixations predicting familiarity and more clustered fixations predicting recollection. These data reveal close links between the autonomic control of pupil responses and eye movement patterns on the one hand and memory encoding on the other. Moreover, the data illustrate quantitative as well as qualitative differences in the incidental visual processing of stimuli, which are differentially predictive of the strength and the kind of memory experienced at recognition.     

Emotional pictures predominate in binocular rivalry

This study used binocular rivalry to examine whether emotionally relevant pictures are processed preferentially in the visual system. Binocular rivalry occurs when two incompatible pictures are presented to both eyes. If the pictures cannot be merged to a single unambiguous percept, binocular rivalry results in an alternation of the two percepts. However, it has been controversial whether emotional picture content can influence a picture's relative predominance. Twenty pairs of emotional and neutral pictures from the International Affective Picture System (IAPS) were presented to 45 healthy participants. As hypothesised, emotional pictures significantly predominated over neutral pictures, both with respect to the first percept and the total viewing time across each trial. We conclude that the relative predominance of emotional pictures in binocular rivalry provides further support for the preferential processing of emotional stimuli in the visual system.     

Recognition memory strength is predicted by pupillary responses at encoding while fixation patterns distinguish recollection from familiarity

Thirty-five healthy participants incidentally encoded a set of man-made and natural object pictures, while their pupil response and eye movements were recorded. At retrieval, studied and new stimuli were rated as novel, familiar (strong, moderate, or weak), or recollected. We found that both pupil response and fixation patterns at encoding predict later recognition memory strength. The extent of pupillary response accompanying incidental encoding was found to be predictive of subsequent memory. In addition, the number of fixations was also predictive of later recognition memory strength, suggesting that the accumulation of greater visual detail, even for single objects, is critical for the creation of a strong memory. Moreover, fixation patterns at encoding distinguished between recollection and familiarity at retrieval, with more dispersed fixations predicting familiarity and more clustered fixations predicting recollection. These data reveal close links between the autonomic control of pupil responses and eye movement patterns on the one hand and memory encoding on the other. Moreover, the data illustrate quantitative as well as qualitative differences in the incidental visual processing of stimuli, which are differentially predictive of the strength and the kind of memory experienced at recognition.     

Reduction of the flash-lag effect in terms of active observation

In the present study, we investigated how observers’ control of stimulus change affects temporal and spatial aspects of visual perception. We compared the illusory flash-lag effects for automatic movement of the stimulus with stimulus movement that was controlled by the observers’ active manipulation of a computer mouse (Experiments 1, 2, and 5), a keyboard (Experiment 3), or a trackball (Experiment 4). We found that the flash-lag effect was significantly reduced when the observer was familiar with the directional relationship between the mouse movement and stimulus movement on a front parallel display (Experiments 1 and 2) and that, although the unfamiliar directional relationship between the mouse movement and stimulus movement increased the flash-lag effect at the beginning of the experimental session, the repetitive observation with the same unfamiliar directional relationship reduced the flash-lag effect (Experiment 5). We found no consistent reduction of the flash-lag effect with the use of a keyboard or a trackball (Experiments 3 and 4). These results suggest that the learning of a specific directional relationship between a proprioceptive signal of hand movements and a visual signal of stimulus movements is necessary for the reduction of the flash-lag effect.     

An external millisecond timer for the Apple Macintosh with applications to cross-modal lexical priming

The circuit and program described in this report allow researchers to use Macintosh personal computers to conduct research that requires timing with millisecond accuracy. This is accomplished with external response keys and an external clock that sends characters through the Macintosh’s serial port. For researchers interested in cross-modal lexical priming tasks, a tachistoscopic slide shutter is incorporated to allow for accurately timed presentation of visual stimuli. Because the visual display and response keys are external to the computer, display and reaction times are not subject to the timing constraints inherent to the keyboard or the Macintosh Event Manager. All circuit diagrams and code are in the public domain.     

Fuzzy picture processing: effects of size reduction and blurring on emotional processing

Previous studies have suggested that picture size reduction affects emotional reactions, possibly because scenes subtending a small visual angle are perceived as being more distant and less relevant compared to larger stimuli. However, pictures that subtend a small visual angle also contain few fine-grained details, which may determine less vivid representations and responses compared to larger and more detailed images. Critically, the present study compared two different types of manipulations, namely size reduction and low-pass spatial filtering, which determined similar detail loss but affected visual angles differently. Affective modulation was assessed using an evaluative task and a behavioral interference task. Results showed that the availability of fine-grained details, independently of visual angle, modulated emotional evaluation. Moreover, interference in an unrelated task was unaffected by either size reduction or low-pass spatial filtering. These findings suggest that high spatial frequencies affect subjective emotional response whereas attentional capture by affective stimuli seems to rely on information that is sufficient to allow a categorization of picture content.     

Investigating the role of response in spatial context learning

Recent research has shown that simple motor actions, such as pointing or grasping, can modulate the way we perceive and attend to our visual environment. Here we examine the role of action in spatial context learning. Previous studies using keyboard responses have revealed that people are faster locating a target on repeated visual search displays (“contextual cueing”). However, this learning appears to depend on the task and response requirements. In Experiment 1, participants searched for a T-target among L-distractors and responded either by pressing a key or by touching the screen. Comparable contextual cueing was found in both response modes. Moreover, learning transferred between keyboard and touch screen responses. Experiment 2 showed that learning occurred even for repeated displays that required no response, and this learning was as strong as learning for displays that required a response. Learning on no-response trials cannot be accounted for by oculomotor responses, as learning was observed when eye movements were discouraged (Experiment 3). We suggest that spatial context learning is abstracted from motor actions.     

Investigating the role of response in spatial context learning

Recent research has shown that simple motor actions, such as pointing or grasping, can modulate the way we perceive and attend to our visual environment. Here we examine the role of action in spatial context learning. Previous studies using keyboard responses have revealed that people are faster locating a target on repeated visual search displays ("contextual cueing"). However, this learning appears to depend on the task and response requirements. In Experiment 1, participants searched for a T-target among L-distractors and responded either by pressing a key or by touching the screen. Comparable contextual cueing was found in both response modes. Moreover, learning transferred between keyboard and touch screen responses. Experiment 2 showed that learning occurred even for repeated displays that required no response, and this learning was as strong as learning for displays that required a response. Learning on no-response trials cannot be accounted for by oculomotor responses, as learning was observed when eye movements were discouraged (Experiment 3). We suggest that spatial context learning is abstracted from motor actions.     

A simple and sensitive method to measure timing accuracy

Timing accuracy in presenting experimental stimuli (visual information on a PC or on a TV) and responding (keyboard presses and mouse signals) is of importance in several experimental paradigms. In this article, a simple system for measuring timing accuracy is described. The system uses two PCs (at least Pentium II, 200 MHz), a photocell, and an amplifier. No additional boards and timing hardware are needed. The first PC, a SlavePC, monitors the keyboard presses or mouse signals from the PC under test and uses a photocell that is placed in front of the screen to detect the appearance of visual stimuli on the display. The software consists of a small program running on the SlavePC. The SlavePC is connected through a serial line with a second PC. This MasterPC controls the SlavePC through an ActiveX control, which is used in a Visual Basic program. The accuracy of our system was investigated by using a similar setup of a SlavePC and a MasterPC to generate pulses and by using a pulse generator card. These tests revealed that our system has a 0.01-msec accuracy. As an illustration, the reaction time accuracy of INQUISIT for a few applications was tested using our system. It was found that in those applications that we investigated, INQUISIT measures reaction times from keyboard presses with millisecond accuracy.     

恐惧与厌恶情绪图片系统的编制：基于两种情绪的区分

基于恐惧与厌恶情绪刺激材料界定模糊的问题,实验一在总结前人研究中实验材料方面混淆恐惧和厌恶的基础上,通过问卷法完成了对恐惧与厌恶图片系统初步的搜集、整理工作;实验二通过进一步测评得到了具有良好信度的恐惧与厌恶情绪图片系统,图片系统中的恐惧与厌恶情绪很好的分离,且图片系统中动物、场景、物体三类图片的恐惧、厌恶程度均存在显著差异,可适用于需要不同种类情绪刺激的具体应用性研究。     

恐惧与厌恶情绪图片系统的编制：基于两种情绪的区分

基于恐惧与厌恶情绪刺激材料界定模糊的问题,实验一在总结前人研究中实验材料方面混淆恐惧和厌恶的基础上,通过问卷法完成了对恐惧与厌恶图片系统初步的搜集、整理工作;实验二通过进一步测评得到了具有良好信度的恐惧与厌恶情绪图片系统,图片系统中的恐惧与厌恶情绪很好的分离,且图片系统中动物、场景、物体三类图片的恐惧、厌恶程度均存在显著差异,可适用于需要不同种类情绪刺激的具体应用性研究。     

Programming without programming: The system Butterfly for professional psychologists

This paper describes a system for creating and running adaptive psychological experiments on IBM PC compatible computers. The system is a collection of programming routines for IBM PC machines (text mode) that allows psychologists to create and edit experiments, collect and handle data, and transfer data into other systems without any programming. Stimulus variables include location, character, time, color, and sound. A special set of criteria is designed to conduct adaptive studies, such as operant conditioning experiments, in which experimental trials must be modified on the basis of a subject’s performance. The system supports multidimensional structural responses with feedback. Reaction and response time and the response contents can be collected from the keyboard, mouse, and game port.