Age and IQ effects on stimulus and response timing.

Normal older participants (aged 60–79 yrs), with known scores on the Culture Fair Intelligence Test, were tested on 4 timing tasks (i.e., temporal generalization, bisection, differential threshold, and interval production). The data were related to the theoretical framework of scalar timing theory and ideas about information processing and aging. In general, increasing age and decreasing IQ tended to be associated with increasing variability of judgments of duration, although in all groups events could be timed on average accurately. In some cases (e.g., bisection), performance differences between the older participants and students nearly 50 years younger used in other studies were negligible. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition effects with categorizable stimulus and response sets.

The repetition effect refers to the finding that reaction times (RTs) are faster on trial n when the stimulus presented and/or the response required is the same as on trial n?–?1 than when it is different. Five experiments examined the importance of stimulus features and response features in obtaining the repetition effect. Exp 1 demonstrated a need for the stimuli to be categorically mapped to responses for a response repetition effect to be observed. Exps 2–5 showed that the repetition effect can be obtained across responding hands when spatial information (Exps 2 and 4) or finger information (Exps 2 and 5) is consistent across hands but not when these sources of information are eliminated (Exp 3). The results are in agreement with expectations developed from salient-features coding and with the inclusive links hypothesis proposed by H. Pashler and G. Baylis (1991). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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 recoding hypothesis (A. Hedge & N. W. A. Marsh, 1975). The results indicate that SS and SR consistency both contribute to the Stroop effect and that they interact. This finding supports models such as the dimensional overlap model (e.g., S. Kornblum & J. W. Lee, 1995) that distinguish between SS and SR overlap. Simulation results from an interactive activation network, modeled after the dimensional overlap model, provide reasonable fits to the experimental data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of stimulus and response variability on S-R correspondence effects.

Six experiments investigated how variability on irrelevant stimulus dimensions and variability on response dimensions contribute to spatial and nonspatial stimulus-response (S-R) correspondence effects. Experiments 1-3 showed that, when stimuli varied in location and number, S-R correspondence effects for location or numerosity occurred when responses varied on these dimensions but not when responses were invariant on these dimensions. These results are consistent with the response-discrimination account, according to which S-R correspondence effects should only arise for a dimension that is used for discriminating between responses in working memory. Experiments 4-6 showed that, when responses varied in location and number, both invariant and variable stimulus number produced correspondence effects in S-R numerosity. In summary, the present results indicate that the usefulness of a particular dimension for response discrimination can be sufficient for producing S-R correspondence effects, whereas variability of a stimulus dimension is not sufficient for producing such effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal stimulus–response compatibility.

The study of element-level stimulus–response compatibility (SRC) has predominantly focused on spatial and symbolic relationships and has involved measures of response time and (dichotomous) error rate. This article explores a new form of SRC that is observed when duration is the relevant feature of both the stimulus and the response, using a more extensive analysis of performance accuracy and variability. The results indicate that element-level SRC generalizes to situations involving time as the relevant dimension of stimuli and responses. Evidence of this was found in all of the extracted measures of performance; however, temporal SRC was shown to have independent effects on when and how accurately a response was made. Implications for SRC research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of irrelevant stimuli: 1. The time course of stimulus–stimulus and stimulus–response consistency effects with Stroop-like stimuli, Simon-like tasks, and their factorial combinations.

[Correction Notice: An erratum for this article was reported in Vol 36(3) of Journal of Experimental Psychology: Human Perception and Performance (see record 2010-10162-008). A key reference for coauthor Gregory T. Stevens’s PhD dissertation was omitted and appears in the correction.] The effects of Simon- and Stroop-like stimuli are examined in isolation and in factorial combinations with different delays between the presentation of the irrelevant and the relevant stimuli. The effects of irrelevant stimuli have different time courses depending on whether they overlap with the relevant stimulus (stimulus-stimulus overlap, Dimensional Overlap [DO] Type 4) or with the response (stimulus-response overlap, DO Type 3). A new, computational, parallel distributed processing (PDP)-type model, DO'97, is presented that is based on the original DO model (S. Kornblum, 1994; S. Kornblum, T. Hasbroucq, & A. Osman, 1990), and it postulates a nonmonotone irrelevant stimulus activation function in addition to 2 temporally ordered, serial, nonindependent stages: a stimulus processing stage and a response production stage. DO'97 is able to simulate the temporal dynamic characteristics of the processes, with good fits to the empirical data of this study and other published studies, at the level of means, variances, and distributional plots. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lexical effects on phonetic categorization: The role of stimulus naturalness and stimulus quality.

A series of experiments was conducted to determine whether the effects of lexical status on phonetic categorization were influenced by stimulus naturalness (replicating M. W. Burton, S. R. Baum, and S. E. Blumstein, 1989, who manipulated the intrinsic properties of the stimuli) and by stimulus quality (presenting the stimuli in white noise). The experiments compared continua varying in voice onset time (VOT) only to continua covarying VOT and amplitude of the burst and aspiration noise in no-noise and noise conditions. Results overall showed that the emergence of a lexical effect was influenced by stimulus quality but not by stimulus naturalness. Contrary to previous findings, significant lexical effects failed to emerge in the slower reaction time (RT) ranges. These results suggest that stimulus quality contributes to lexical effects on phonetic categorization, whereas stimulus naturalness does not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A model for adaptation-level effects on stimulus generalization.

Presents a quantitative model of adaptation-level (AL) effects on stimulus generalization and integrates results from single stimulus, go–no-go, and choice discrimination training paradigms. The model accurately predicts (1) the gradualness of the shift in responding during the course of asymmetrical generalization testing, (2) the relation between the degree of asymmetry and the amount of shift, (3) the effect of overrepresenting certain stimuli during testing, and (4) the effect of varying the amount of training. With the discrimination training paradigms, the effects of the degree of separation between the training stimuli and of the relative frequency of their presentation during training and subsequent generalization testing are consistent with an extension of the basic model. Finally, new research is described affirming the applicability of the AL model to several infrahuman species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exposure effects may not depend on stimulus recognition.

Compared the applicability of M. H. Birnbaum and B. A. Mellers' (see PA, Vol 64:00000) 1-factor (subjective recognition) model with the present author's (see record 1979-23525-001) 2-factor model to data on the role of stimulus recognition in the mere exposure phenomenon. Results of a series of linear structural equation analyses show that the 2-factor model provided a significantly greater degree of fit. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some effects of immediate versus randomly delayed shock on an instrumental response and cognitive processes.

"… Ss were required… to guess whether a right or left light would go on, indicating their guesses by pressing a lever below the appropriate light. Trials… [involved] non-shock… . [and] an immediate shock (IS) every time he pressed one lever and a randomly delayed shock (RDS) every time he pressed the other lever, irrespective of whether he guessed correctly or incorrectly." Results: a significant avoidance of the lever leading to RDS, a significantly greater number of Ss judged the RDS as more unpleasant than IS, a marked impairment of Ss' recall of stimulus events and their behavior during the shock trials. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relative effects of wound healing and mechanical stimulus on early bone response to porous-coated implants

We hypothesized that early bone adaptation to well fixed porous-coated implants is influenced more by wound healing than by mechanical loading. To test this hypothesis, two groups of dogs with identical, hydraulically controlled porous-coated implants interference fit within distal femoral trabecular bone were used. One group had no load: the other had 35 N of load applied to the implants. At 5 weeks after surgery, the resulting adaptation of bone around the implants was quantified on a cellular basis by cytochemical analysis of type-I procollagen synthesis and on a structural basis using three-dimensional micro-computed tomography imaging. The percentage of trabecular surfaces covered by osteoblasts expressing type-I procollagen was significantly increased in bone surrounding the implant in both groups compared with contralateral control bone tissue. There was no difference between the groups with no load or 35 N of load. In addition, measures of trabecular bone structure did not differ significantly between the load and no-load groups. Taken together, these results suggest that wound healing plays a much greater role in the early response of bone to well fixed porous-coated implants than does mechanical stimulus.     

The effect of stimulus and background factors on the volunteering response.

"Deriving its orientation from Helson's theory of adaptation level, the present experiment elaborates the former by systematically studying the contribution of the stimulus in the immediate focus of attention in conjunction with presentation of background stimuli in the form of the responses of other people. The general plan of the study called for creating test situations within which invitations to participate in a psychological experiment that varied in strength were tendered to Ss after they had seen the reaction of another person to the same request, with the observed reaction also being subjected to systematic variation." The Ss were 135 males using a university library. It was found that both stimulus and background factors were significantly related to the volunteering response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Encoding and external-storage effects on writing processes.

Across 4 experiments, undergraduate students viewed a 19-min videotape lecture about types of creativity and then wrote a compare-and-contrast essay for 25 min. In Exps 1 (immediate writing) and 2 (delayed writing), Ss either listened or took notes under 1 of 3 note-taking formats and then wrote with or without notes. In both experiments, Ss writing from their own notes (encoding plus external storage) composed more organized and lengthier essays than Ss writing without their notes (encoding only). Exps 3 and 4 examined the external-storage effect separately from the encoding effect. In delayed writing (Exp 4), Ss composing from provided notes wrote lengthier essays than Ss composing without notes. Results support the effects of external storage and encoding plus external storage on writing processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The moderating effects of stimulus valence and arousal on memory suppression.

This study examined the separate and combined effects of stimulus valence and arousal on retrieval inhibition. Participants performed Anderson and Green's (2001) memory suppression task with stimuli varying across dimensions of valence and arousal. Memory was tested through free and cued recall as well as speeded recognition. Results showed that both stimulus valence and arousal influenced the extent to which participants successfully inhibited retrieval, but not in the ways anticipated. Specifically, the strongest inhibition effects were for highly arousing, pleasant words. In addition, unpleasant stimuli that were suppressed were better recalled during both cued and free-recall tasks than pleasant stimuli that were suppressed. Across all tests of memory performance, there were no significant differences between the experimental conditions for highly arousing, unpleasant words. The implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of stimulus similarity and response criterion on successive discrimination reversal learning.

In a study with 30 naive domestic pigeons, 2 levels of stimulus similarity and 2 levels of criterion were factorially combined in a free-operant, successive presentation of stimuli, successive discrimination reversal (SDR) involving chromatic stimuli. Both variables were found to have significant effects on SDR performance. Groups having the less rigorous criterion showed either no improvement or a deterioration in performance, depending on discrimination difficulty. Transfer to a line-angle discrimination revealed no differences between SDR groups and an original-learning control group in time to criterion required to learn this problem. All SDR groups were superior to the control group on the reversal of this problem, but there were no differences between SDR groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus–response compatibility as a function of stimulus code and response modality.

The concept of stimulus-response compatibility can be differentiated into set-level and element-level compatibility. The relation between these 2 types of compatibility was examined by varying stimulus code (spatial or verbal) and response modality (manual or vocal) in 2-choice tasks that used left-right stimuli and left-right responses. Element-level compatibility was an increasing function of set-level compatibility and larger for verbal than for spatial stimuli. The positive relation between set- and element-level compatibility was due to differences for the congruent mapping but not the incongruent mapping. The results can be characterized in terms of (a) a continuum along which the relative compatibility of the responses with spatial and verbal stimuli varies and (b) a dual-route conception of response selection in which a direct, or automatic, route is involved only when a congruent mapping is in effect. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of stimulus duration and intensity on simple reaction time and response force.

Previous research indicates that response force increases with stimulus intensity in simple reaction time (SRT) tasks. This result contradicts the common view that the perceptual system activates the motor system via a punctate go signal of fixed size. An elaborated view assumes that the size of the go signal depends on stimulus intensity so that more intense stimuli yield more forceful responses. In order to examine the latter hypothesis, the present experiments manipulated stimulus duration as well as intensity. Response force increased with duration even beyond a critical value of about 60 ms at which stimulus duration no longer affected SRT. In addition, increasing the duration of a stimulus also increased the duration of force output. These findings argue against models with punctate transmission of activation to the motor system. Certain continuous models and variable output models with prolonged go signals provide acceptable accounts of these effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic stimulus–response translation in dual-task performance.

In bottleneck models of overlapping-task performance, stimulus-response translation for secondary tasks is postponed until the primary response is selected. If this is so, then compatibility between the secondary and primary responses, or between the secondary response and the primary stimulus, should not affect primary-task performance. Yet such effects were demonstrated in 5 dual-task experiments combining primary manual and secondary vocal tasks: Pronounced effects of compatibility between the secondary and primary response and between the secondary response and primary stimulus were found on primary-task performance. The latter effect was also found with the lowest level of an extensive stimulus onset asynchrony variation, when the secondary task was not speeded, and even when the 2 tasks were performed on different trials. Findings suggest that secondary responses were activated before primary response selection was completed and thus support an automatic-translation hypothesis holding that, although eventual response selection may be serial, stimulus-response translation is performed in parallel. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of partial stimulus information in response processing.

We examined the reaction time (RT) benefit that is obtained when salient features of the stimulus set and response set correspond. Components of the event-related brain potentials were used to measure the timing of stimulus-related and response-related processes in order to determine the locus of this effect. Of particular importance was the development of a new index of selective response preparation, the corrected motor asymmetry (CMA). We found no evidence for the use of preliminary, partial stimulus information in response preparation. These results suggest that the benefit is located primarily in response selection processes and probably reflects a more efficient algorithm for stimulus-response translation. Also, we found trial-to-trial variability in the duration of response selection to be the major determinant of variability in RT, whereas the durations of subsequent response-related processes were relatively invariant. Implications of these results for discrete and continuous models of choice reaction performance are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral control, aversive stimulus frequency, and pituitary-adrenal response.

Six female Long-Evans rats were trained to leverpress under a free-operant shock postponement schedule, and each S was linked to a control that received shock whenever the S did to test the hypothesis that the pattern of corticosteroid response would be affected by both the frequency of shock received and the availability of behavioral control. The shock postponement interval (R-S) was varied (5, 10, 20, 40, or 80 sec) over blocks of sessions. Corticosteroid levels were taken prior to training and before and after selected sessions. Results show that frequency of shock had no major impact on physiological processes controlling the corticosteroid response; however, when Ss had the opportunity to control aversive events, a change in corticosteroid response was evident relative to controls. The rates of responding and of shock were inversely related to the R-S interval. Corticosteroid levels were unrelated to the R-S parameter. Corticosteroid levels of Ss were significantly higher than basal levels at the beginning of a session; by the end of a session, these levels were significantly reduced, although still above basal levels. These results were reversed for controls. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)