Stimulus-response compatibility effects in go-no-go tasks: a dimensional overlap account.

According to the automatic response activation hypothesis of the dimensional overlap (DO) model (Kornblum, Stevens, Whipple, & Requin, 1999), stimulus-response compatibility effects are expected to occur in go-no-go tasks. This prediction is confirmed in two experiments in which subjects moved a hand to one side of the field on presentation of a go stimulus. Although the direction of movement was known in advance and the spatial attribute of the go stimuli was irrelevant to the go-no-go decision, the subjects' response time was shorter when the spatial attribute to the go stimulus corresponded to that of the response than when it did not.

A parallel distributed processing model of stimulus-stimulus and stimulus-response compatibility.

A parallel distributed processing (PDP) model is proposed to account for choice reaction time (RT) performance in diverse cognitive and perceptual tasks such as the Stroop task, the Simon task, the Eriksen flanker task, and the stimulus-response compatibility task that are interrelated in terms of stimulus-stimulus and stimulus-response overlap (Kornblum, 1992). In multilayered (input-intermediate-output) networks, neuron-like nodes that represent stimulus and response features are grouped into mutually inhibitory modules that represent stimulus and response dimensions. The stimulus-stimulus overlap is implemented by a convergence of two input modules onto a common intermediate module, and the stimulus-response overlap by direct pathways representing automatic priming of outputs.

The effects of stimulus-response mapping and irrelevant stimulus-response and stimulus-stimulus overlap in four-choice Stroop tasks with single-carrier stimuli.

The purpose of this study was to investigate whether and how stimulus-stimulus (SS) and stimulus-response (SR) consistency and SR congruence effects combine to produce the Stroop effect. Two experiments were conducted with 4-choice tasks in which SS and SR consistency and SR congruence effects were examined in isolation as well as in the Stroop task. The experiments were so designed as to remove the confound between SS and SR consistency that is ordinarily found in standard Stroop tasks and to pit SS consistency against the logical recording hypothesis (A.

Neuronal correlates of sensorimotor association in stimulus-response compatibility.

Neuronal mechanisms underlying stimulus-response (S-R) associations in S-R compatibility tasks were identified in 2 experiments with monkeys. Visual stimuli were presented on the left and right calling for left-right movements under congruent and incongruent S-R mapping instructions. High- and low-pitched tones calling for left-right movements were presented to the left and right ear, and the stimulus side was irrelevant.

Isolation of specific interference processing in the Stroop task: PET activation studies.

The Stroop task, in which subjects must name the color of letters that spell color words different than the color-to-be-named, provides an important experimental paradigm for the study of selective attention. Cerebral blood flow activation studies have not always demonstrated consistent activation patterns; inconsistent results may reflect nonspecific responses, such as arousal or anticipation, rather than cerebral networks specific to Stroop interference processing. In order to identify regions consistently implicated in Stroop interference processing, we undertook two experiments with a Stroop interference paradigm and contrasting lexical and nonlexical control conditions.

Dynamics of single neuron activity in monkey primary motor cortex related to sensorimotor transformation.

We investigated the dynamics of neuronal activity related to sensorimotor transformation during single experimental trials of a given stimulus-response (S-R) association task. A monkey was trained to perform wrist extension/flexion movements in the horizontal plane to align a pointer with a visual target while single unit activity in the primary motor cortex (MI) was being recorded. The stimulus was a colored light-emitting diode (LED) presented to either the left or right of a central reference point.

Negative priming and stimulus-response compatibility.

The subjects in this study made incongruent naming responses to words and pictures that were presented on alternate trials (e.g., say "car" toBIKE).

Facilitation and interference of selective attention in schizophrenia.

Theories of attentional impairment in schizophrenia predict excessive interference in selective attention tasks, such as the Stroop task, where subjects must name the color of words which spell colors different than the to-be-named-color. However, a recent study actually found greater facilitation, i.e.

Stimulus-response compatibility with relevant and irrelevant stimulus dimensions that do and do not overlap with the response.

Five experiments were conducted using 4- and 6-choice stimulus-response compatibility tasks with graphic and alphabetic stimuli, and keypress and verbal responses. A comparison of performance with compatible, incompatible, and neutral conditions shows that when a stimulus set is perceptually, conceptually, or structurally similar to a response set, (a) mean reaction times (RTs) are faster when individual stimuli and responses match than when they do not match, (b) this is true whether the stimulus and response sets are similar on relevant or irrelevant dimensions, (c) this "compatibility effect" is greater when the dimensions are relevant than when they are irrelevant, and (d) whether the dimensions are relevant or irrelevant, the faster RTs are due to a facilitative process and the slower RTs to an interfering process. These results are accounted for by the dimensional overlap model.

Neuronal coding of stimulus-response association rules in the motor cortex.

Two monkeys were trained to perform wrist movements to align a pointer with visual targets. In the spatially 'compatible' condition, monkeys had to point at the target position (left/right), whereas in the 'incompatible' condition, they had to point at the position opposite to the target. A large proportion of neurones recorded in the primary motor cortex showed changes in activity according to either the side of the target or the side of the movement.

Changes in medial cortical blood flow with a stimulus-response compatibility task.

Previous work has suggested that human subjects engaged in tasks, like the Stroop task, that require response selection utilize the medial frontal cortex. We used positron emission tomography to measure blood flow changes in a stimulus-response compatibility task designed to maximize the demand on response selection processes. We report significant activation in the cingulate sulcus (Brodman's area 32) and a correlation of activity in this region with faster response time for an incongruent stimulus-response task.

The way irrelevant dimensions are processed depends on what they overlap with: the case of Stroop- and Simon-like stimuli.

According to the dimensional-overlap model (Kornblum, 1992), irrelevant dimensions that overlap with a stimulus dimension (e.g., Stroop-type stimuli) are processed by a different stage than those that overlap with the response (e.

Eye-hand coordination: oculomotor control in rapid aimed limb movements.

Three experiments are reported in which Ss produced rapid wrist rotations to a target while the position of their eyes was being monitored. In Experiment 1, Ss spontaneously executed a saccadic eye movement to the target around the same time as the wrist began to move. Experiment 2 revealed that wrist-rotation accuracy suffered if Ss were not allowed to move their eyes to the target, even when visual feedback about the moving wrist was unavailable.

Dimensional overlap: cognitive basis for stimulus-response compatibility--a model and taxonomy.

The classic problem of stimulus-response (S-R) compatibility (SRC) is addressed. A cognitive model is proposed that views the stimulus and response sets in S-R ensembles as categories with dimensions that may or may not overlap. If they do overlap, the task may be compatible or incompatible, depending on the assigned S-R mapping.

Does motor programming necessitate response execution?

The complexity of a movement is known to affect the time it takes to initiate the movement. This effect is thought to reflect changes in the duration of processes that operate on a motor program. This question addressed here is whether programming a movement compels the start of its overt execution.

Speed and accuracy of saccadic eye movements: characteristics of impulse variability in the oculomotor system.

Dynamic characteristics observed in the trajectories of saccadic eye movements reveal systematic variability of the force pulses used to move the eyes. This variability causes saccades to exhibit a linear speed-accuracy trade-off: As the average distance and duration of saccades toward specified target points increase, the standard deviations of saccadic-movement endpoints increase linearly with the saccades' average velocity. The linear trade-off, and other observed stochastic properties of saccades, may be attributed to noise in neuromotor processes and may be described in terms of an impulse-variability model originally designed for characterizing limb movements.

The point of no return in choice reaction time: controlled and ballistic stages of response preparation.

A countermanding procedure and race model are used to assess separately the effects of experimental factors before and after the "point of no return" in response preparation. The results reveal details about processes that so closely precede the initiation of movement that they cannot be inhibited. These processes appear to be affected by the repetition of stimulus-response pairs, but not by the physical or semantic properties of the stimuli.

Evaluation of a language program for young autistic children.

This report presents retrospective data comparing an individualized language development program for preschool autistic children receiving language remediation (experimental subjects) with a group receiving the basic school curriculum only (control subjects). All findings favored the language remediation group, as indicated: (1) experimental subjects made significant gains in one year while the control group required two years; (2) after one year, experimental subjects surpassed controls on four measures; (3) only experimental subjects made significant gains in communicative speech, noteworthy because interpersonal interaction is so difficult for the autistic child; and (4) after two years, 58% of the experimental subjects, but only 14% of the controls, had mastered all seven skills. These results support the hypothesis that an individualized language remediation program facilitates the acquisition of prelinguistic and linguistic skills.