Extendable high-speed stimulus generation and recording on the Macintosh computer

A new visual electrophysiology and eye-movement laboratory was developed with three goals in mind: (1) rapid execution speed for quick acquisition of data from infant subjects, (2) ease of operation by experimenters, and (3) modularity and flexibility. A powerful system composed of two linked Macintosh computers was constructed in which one computer was used solely to generate visual stimuli and the second solely to record subjects’ responses, allowing recording to execute at maximum speed without being slowed by stimulus graphics generation. A single program on the recording computer allowed the experimenter to choose the stimulus and recording parameters. The two computers intercommunicated via a local EtherNet network to coordinate recording and signal averaging. This paper presents design principles and specific programming techniques relevant to any Macintosh system that must rapidly acquire physiological recordings while simultaneously displaying sensory stimuli.     

PsychLib: A library of machine language routines for controlling psychology experiments on the Apple Macintosh computer

The hardware and system software of the Apple Macintosh computer are described, and their implications for conducting psychological research is discussed. A library of machine language routines for presenting auditory and visual stimuli and recording response latencies is described.     

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.     

Pupillometry in Infancy Research

The human pupil is a small opening in each eye that dilates in response not only to changes in luminance, but also to novel events. Therefore, changes in pupil diameter are an attractive measure in studies on infants’ and young children’s physical and social cognition. However, designing and interpreting pupillometry studies for developmental populations come with caveats. Here we give an overview of how psychologically induced changes in pupil diameter have been investigated and interpreted in developmental studies. We highlight the methodological challenges when designing experiments for infants and young children and provide several suggestions to address common problems. The fact that pupillometry provides a sensitive measure of the time course of responses to novelty extends the scope of possibilities for researchers studying infant cognition and development.     

瞳孔是心灵的窗口吗?——瞳孔在心理学研究中的应用及测量

瞳孔大小是眼动研究中一个重要的参数指标, 在一定程度上能够反映人的心理活动并影响他人的心理与行为。一方面, 瞳孔变化受到自上而下的知觉与注意、情绪与动机、心理努力、社会认知与发展等因素的影响, 另一方面, 大瞳孔能引起他人更多的积极评价和积极行为。瞳孔的神经机制(蓝斑-去甲肾上腺素系统)和自适应增益理论解释了瞳孔与心理之间存在紧密联系的原因。瞳孔测量(pupillometry)作为一种有效的眼动追踪方法有助于理解瞳孔与心理的关系, 研究者在测量瞳孔时需要关注无关变量(如亮度、注视位置), 原始数据处理(如基线校正、眨眼处理)及瞳孔指标选取(如瞳孔直径、震颤频率)等问题, 未来研究应继续探讨瞳孔与其他心理之间的关系, 并探索更有效地处理和使用瞳孔指标的方法。     

Sensation seeking and stimulus intensity as modulators of cortical,cardiovascular, and electrodermal response: A cross-modality study

Previous studies have related the trait of sensation seeking to augmenting of the evoked potential (EP) in both visual and auditory modalities and to electrodermal and heart rate (HR) orienting and defensive reactions. The present study examined all of these phenomena in the same sample of subjects in order to replicate previous findings, and investigate cross-modality consistency and relationships between cortical and peripheral responses. Fifty-four male subjects, scoring high or low on the Disinhibition Sensation Seeking Scale, were exposed to 4 intensities of auditory stimuli (tones) on one occasion and visual stimuli (light flash) on another. Two interstimulus (ISIs) intervals were used for each set of stimuli: first a 17 sec series, and then a 2 sec series. High disinhibitors showed EP augmenting and lows reducing on 3 of the 4 series; differences were significant on two of them. High disinhibitors showed stronger orienting (deceleratory) HR responses to visual and auditory stimuli while lows showed stronger defensive (acceleratory) HR responses. HR responses were significantly correlated across stimulus modalities. Auditory and visual EP slope measures were correlated only for the long ISI series.     

Pupillary Stroop effects

We recorded the pupil diameters of participants performing the words’ color-naming Stroop task (i.e., naming the color of a word that names a color). Non-color words were used as baseline to firmly establish the effects of semantic relatedness induced by color word distractors. We replicated the classic Stroop effects of color congruency and color incongruency with pupillary diameter recordings: relative to non-color words, pupil diameters increased for color distractors that differed from color responses, while they reduced for color distractors that were identical to color responses. Analyses of the time courses of pupil responses revealed further differences between color-congruent and color-incongruent distractors, with the latter inducing a steep increase of pupil size and the former a relatively lower increase. Consistent with previous findings that have demonstrated that pupil size increases as task demands rise, the present results indicate that pupillometry is a robust measure of Stroop interference, and it represents a valuable addition to the cognitive scientist’s toolbox.     

Pupillometry reveals increased pupil size during indirect request comprehension

Fluctuations in pupil size have been shown to reflect variations in processing demands during lexical and syntactic processing in language comprehension. An issue that has not received attention is whether pupil size also varies due to pragmatic manipulations. In two pupillometry experiments, we investigated whether pupil diameter was sensitive to increased processing demands as a result of comprehending an indirect request versus a direct statement. Adult participants were presented with 120 picture–sentence combinations that could be interpreted either as an indirect request (a picture of a window with the sentence “it's very hot here”) or as a statement (a picture of a window with the sentence “it's very nice here”). Based on the hypothesis that understanding indirect utterances requires additional inferences to be made on the part of the listener, we predicted a larger pupil diameter for indirect requests than statements. The results of both experiments are consistent with this expectation. We suggest that the increase in pupil size reflects additional processing demands for the comprehension of indirect requests as compared to statements. This research demonstrates the usefulness of pupillometry as a tool for experimental research in pragmatics.     

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.     

VSearch Color: Full-color visual search experiments on the Macintosh II

We describe an update to our visual search software for the Macintosh line of computers. The new software, VSearch Color, gives users access to the full-color capabilites of the Macintosh II line. One of the key features of the new software is its ability to treat graphics information separately from color information. This makes it easy to study color independently of form, to design experiments based on isoluminant stimuli, and to incorporate texture segregation, visual identification, number discrimination, adaptation, masking, and spatial cuing into the basic visual search paradigm.     

Processing motion implied in language: eye-movement differences during aspect comprehension

Previous research on language comprehension has used the eyes as a window into processing. However, these methods are entirely reliant upon using visual or orthographic stimuli that map onto the linguistic stimuli being used. The potential danger of this method is that the pictures used may not perfectly match the internal aspects of language processing. Thus, a method was developed in which participants listened to stories while wearing a head-mounted eyetracker. Preliminary results demonstrate that this method is uniquely suited to measure responses to stimuli in the absence of visual stimulation.     

VSearch: Macintosh software for experiments in visual search

In this paper, we describe software that turns a Macintosh computer into an off-the-shelf tool for experiments on visual search. Our design goals included portability (between members of the Macintosh computer family and between various research settings), user-friendliness (equivalent to Macintosh programming standards), flexibility (to allow replication and extension of important experiments on visual search), and adaptability (very short design-to-data and data-to-analysis turnaround times). We describe how the software meets these goals in three major phases of an experiment: stimulus construction, experimental control, and statistical analysis. We then list several landmark studies of visual search that can be easily designed and extended with the software. Finally, we outline plans for expanding the experimental variations that will be supported in future versions of the software.     

Temporal constraints on the McGurk effect

Three experiments are reported on the influence of different timing relations on the McGurk effect. In the first experiment, it is shown that strict temporal synchrony between auditory and visual speech stimuli is not required for the McGurk effect. Subjects were strongly influenced by the visual stimuli when the auditory stimuli lagged the visual stimuli by as much as 180 msec. In addition, a stronger McGurk effect was found when the visual and auditory vowels matched. In the second experiment, we paired auditory and visual speech stimuli produced under different speaking conditions (fast, normal, clear). The results showed that the manipulations in both the visual and auditory speaking conditions independently influenced perception. In addition, there was a small but reliable tendency for the better matched stimuli to elicit more McGurk responses than unmatched conditions. In the third experiment, we combined auditory and visual stimuli produced under different speaking conditions (fast, clear) and delayed the acoustics with respect to the visual stimuli. The subjects showed the same pattern of results as in the second experiment. Finally, the delay did not cause different patterns of results for the different audiovisual speaking style combinations. The results suggest that perceivers may be sensitive to the concordance of the time-varying aspects of speech but they do not require temporal coincidence of that information.     

Auditory,visual, and cross-modal negative priming

Auditory, visual, and cross-modal negative priming was investigated using a task in which participants judged whether stimuli were animals or musical instruments. Negative priming was observed, but only if the attended and the ignored primes evoked different responses. This pattern—negative priming after conflict, but not after nonconflict, primes—was demonstrated with visual stimuli and replicated with auditory stimuli, as well as across modalities, both auditory to visual and visual to auditory. Implications for theories of negative priming are discussed.     

Spontaneous number discrimination of multi-format auditory stimuli in cotton-top tamarins (Saguinus oedipus)

Studies using operant training have demonstrated that laboratory animals can discriminate the number of objects or events based on either auditory or visual stimuli, as well as the integration of both auditory and visual modalities. To date, studies of spontaneous number discrimination in untrained animals have been restricted to the visual modality, leaving open the question of whether such capacities generalize to other modalities such as audition. To explore the capacity to spontaneously discriminate number based on auditory stimuli, and to assess the abstractness of the representation underlying this capacity, a habituation-discrimination procedure involving speech and pure tones was used with a colony of cotton-top tamarins. In the habituation phase, we presented subjects with either two- or three-speech syllable sequences that varied with respect to overall duration, inter-syllable duration, and pitch. In the test phase, we presented subjects with a counterbalanced order of either two- or three-tone sequences that also varied with respect to overall duration, inter-syllable duration, and pitch. The proportion of looking responses to test stimuli differing in number was significantly greater than to test stimuli consisting of the same number. Combined with earlier work, these results show that at least one non-human primate species can spontaneously discriminate number in both the visual and auditory domain, indicating that this capacity is not tied to a particular modality, and within a modality, can accommodate differences in format.     

Tachistoscopic software for the Macintosh

The emulation of a tachistoscope with a Macintosh microcomputer and Pascal language is presented here. The software described is a complete program for the presentation of textual stimuli on the Macintosh screen and includes the recording of reaction times. The stimulus coordinates on the screen are user defined and variable from trial to trial for specific visual angles. The position of a fixation point on the screen and the distance between the subject and the plane of the screen, as well as the particular screen resolution, are taken into account in computing the visual angle.     

ArtWare: Macintosh multimedia software for aesthetics research

This paper describes ArtWare, a HyperCard stack for the Apple Macintosh that allows researchers to configure and run simple experiments in visual aesthetics. ArtWare allows researchers to (1) choose paintings or other works of art from commercially available laser discs to use as stimuli, (2) create and edit sets of semantic differential response scales, and (3) create an experiment stack that randomizes the presentation of stimuli and scales as well as collects data from subjects. In addition, the paper discusses revisions planned for the current software to broaden its utility to areas beyond visual aesthetics.     

On the role of space and time in auditory processing

Unlike visual and tactile stimuli, auditory signals that allow perception of timbre, pitch and localization are temporal. To process these, the auditory nervous system must either possess specialized neural machinery for analyzing temporal input, or transform the initial responses into patterns that are spatially distributed across its sensory epithelium. The former hypothesis, which postulates the existence of structures that facilitate temporal processing, is most popular. However, I argue that the cochlea transforms sound into spatiotemporal response patterns on the auditory nerve and central auditory stages; and that a unified computational framework exists for central auditory, visual and other sensory processing. Specifically, I explain how four fundamental concepts in visual processing play analogous roles in auditory processing.     

Testing a queue hypothesis for the processing of global and local information.

To test whether the advantage for global features in visual perception is stationary throughout the course of processing or is superseded by a local advantage, 6 experiments were conducted in which subjects responded to auditorially presented letter names, while viewing compound visual stimuli. The consistencies of the 2 levels of the compound letters with the auditory stimuli were varied. The requirement with respect to the visual stimulus was manipulated between experiments. The onset asynchrony (SOA) between the visual stimulus and the auditory one was randomized within blocks. Interaction of SOA with consistency of either of the globality levels with the auditory stimulus would indicate lack of stationarity. No such indication was found. Several findings suggest global advantage. The results hold across 3 exposure durations. Findings support the hypothesis of global precedence as well as the claim that it is stationary.