A horse race between independent processes: evidence for a phantom point of no return in preparation of a speeded motor response

Electromyographic (EMG) data show that a speeded elbow extension response can be interrupted at any time after its execution. Submaximal, or partial, EMG data are also observed in some cases, from which 2 alternatives were considered. The partial response might in fact be interrupted early in response production or, alternately, it might arise from stopping processes that incompletely suppress the response production processes prior to their execution. An interrupted response is easily accounted for by a horse race between independent response production and stopping processes, whereas a partial response can only be reconciled if leakage between the two processes is allowed for. If the distinction between an interrupted and a partial response is correct, then the data yielded evidence for a phantom point of no return that locates late in the premotor component of the response and, thus, prior to the onset of EMG activity.     

In search of the point of no return: The control of response processes.

Control processes underlying response inhibition were examined. Six Ss performed a visual choice reaction task and were occasionally presented with a tone that told them to withhold the response. Reaction time results were in agreement with a model that assumes a race between response activation and response inhibition processes. Event-related brain potentials, electromyogram, and continuous response measures showed that responses could be interrupted at any time. Evidence was obtained for two inhibitory mechanisms: inhibition of central activation processes and inhibition of transmission of motor commands from central to peripheral structures. Results have implications for the distinction between controlled and ballistic processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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

Used a countermanding procedure and race model to assess separately the effects of experimental factors before and after the "point of no return" in response preparation (i.e., where the decision to move becomes irrevocable) in 3 experiments with 22 undergraduates. 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. Findings support a model of response preparation in which (a) response inhibition depends on the outcome of a race between independent excitatory and inhibitory processes and (b) reaction time (RT) is the sum of the durations of at least 2 stages, separated by the point of no return. (54 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Stereotyping and evaluation in implicit race bias: Evidence for independent constructs and unique effects on behavior.

Implicit stereotyping and prejudice often appear as a single process in behavior, yet functional neuroanatomy suggests that they arise from fundamentally distinct substrates associated with semantic versus affective memory systems. On the basis of this research, the authors propose that implicit stereotyping reflects cognitive processes and should predict instrumental behaviors such as judgments and impression formation, whereas implicit evaluation reflects affective processes and should predict consummatory behaviors, such as interpersonal preferences and social distance. Study 1 showed the independence of participants' levels of implicit stereotyping and evaluation. Studies 2 and 3 showed the unique effects of implicit stereotyping and evaluation on self-reported and behavioral responses to African Americans using double-dissociation designs. Implications for construct validity, theory development, and research design are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence of preliminary response preparation from a divided attention task.

In a divided attention situation, preliminary response activations produced by stimuli on one channel were revealed through their effects on responses to stimuli on a secondary probe channel. Subjects performed concurrent but independent four-choice reaction-time tasks using the same four response fingers (middle and index fingers on both hands). In the main task, targets were large and small Ss and Ts, and medium-sized Ss and Ts sometimes appeared as distractors. Targets in the probe task were squares differing in location. A response to a probe square was faster if a distractor letter presented just before it had the same name as the target letter corresponding to that square (i.e., assigned to the same response key) than if the distractor letter had a different name—a result indicating that distractor letters cause partial response preparation. The timecourse of the effect demonstrated that preparation was based on preliminary information about distractor name that was available before distractor size had been determined. The results support models in which response preparation can sometimes begin before stimulus recognition has finished. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strategic control in word reading: Evidence from speeded responding in the tempo-naming task.

To investigate strategic control over response initiation in word reading, the authors introduce the tempo-naming task. Relative to baseline performance in the standard-naming task, participants were induced to respond with faster latencies, shorter durations, and lower levels of accuracy by instructing them to time response initiation with an experimentally controlled tempo. The tempo response cue attenuated stimulus effects, and as faster tempos reduced latencies, the number of spelling-sound errors remained constant, whereas the number of word, nonword, and articulatory errors increased. To explain these results, the authors propose input gain as a mechanism of control over processing speed. The experimenters sketch how input gain could account for the current results as well as for the results from stimulus-blocking experiments testing the route emphasis and time criterion hypotheses of strategic control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mapping the identity of a viewed hand in the motor system: Evidence from stimulus–response compatibility.

Brain-imaging research has shown that a viewed acting hand is mapped to the observer's hand representation that corresponds with the identity of the hand. In contrast, behavioral research has suggested that rather than representing a seen hand in relation to one's own manual system, it is represented in relation to the midline of an imaginary body. This view was drawn from the finding that indicated that the posture of the viewed hand determines how the hand facilitates responses. The present study explored how an identity of a viewed static hand facilitates responses by varying the onset time and the posture of the hand. The results were in line with the view that an observed hand can activate the observer's hand representation that corresponds with the identity of the hand. However, the posture of the hand did not influence these mapping processes. What mattered was the perspective (i.e., egocentric vs. allocentric) from which the hand was viewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polarity correspondence: A general principle for performance of speeded binary classification tasks.

Differences in performance with various stimulus-response mappings are among the most prevalent findings for binary choice reaction tasks. The authors show that perceptual or conceptual similarity is not necessary to obtain mapping effects; a type of structural similarity is sufficient. Specifically, stimulus and response alternatives are coded as positive and negative polarity along several dimensions, and polarity correspondence is sufficient to produce mapping effects. The authors make the case for this polarity correspondence principle using the literature on word-picture verification and then provide evidence that polarity correspondence is a determinant of mapping effects in orthogonal stimulus-response compatibility, numerical judgment, and implicit association tasks. The authors conclude by discussing implications of this principle for interpretation of results from binary choice tasks and future model development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distorted memory for examplars of a social structure: Evidence for schematic memory processes.

Exp I with 21 undergraduates demonstrated distorted memory for exemplars of a social structure. Slides, each depicting 1 of 6 athletes finishing in an athletic event, were arranged into episodes consisting of from 2 ("{twos}") to 5 ("{fives}") slides, the 1st slide in an episode representing 1st place, the 2nd slide, 2nd place, and so on. During acquisition, {twos, threes, fours}, and {fives} consistent with a linear ordering of skill were presented. During recognition, {olds} (episodes previously seen), {news} (novel episodes consistent with the ordering), and {noncases} (episodes violating the ordering) were shown as {twos, threes, fours}, and {fives}. {olds} and {news} were equally confidently recognized; {noncases} were rejected. Recognition confidence for {olds} and {news} was a positive, linear function of episode length. Two forms of memory distortion occurred: {new fives} were falsely recognized, and they were recognized more confidently than {old twos}. Ss apparently constructed an all-encompassing linear-ordering schema that determined recognition performance, since recognition confidence was invariantly a positive function of similarity to the schema. Exp II (15 undergraduates) disconfirmed 2 alternative explanations and confirmed that schema construction occurred. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Home alone: the role of cognition in return to independent living

OBJECTIVE: To identify unique predictors of the ability to return to living alone in geriatric patients undergoing medical rehabilitation. DESIGN: Of 900 consecutive geriatric patients entering medical rehabilitation, 372 were identified as living alone before admission. Data were collected on functional status, cognition, demographics, and discharge disposition. SETTING: A freestanding medical rehabilitation facility. All patients were admitted to a geriatric rehabilitation unit. PATIENTS: Patients aged 60 to 99, identified as having lived alone before admission, were included. As standard procedure, patients underwent functional and cognitive assessment, and medical records were reviewed. MAIN OUTCOME MEASURE: Logistic regression analysis was used to evaluate predictors of discharge disposition, including demographic variables, medical burden, the Functional Independence Measure (FIM), and the Dementia Rating Scale (DRS). RESULTS: Both the FIM and DRS provided significant and unique variance in prediction of discharge disposition. Patients discharged home alone performed similarly to those discharged with supervision on FIM motor items but higher on FIM social cognition items, emphasizing the strong role of cognition in discharge disposition. Patients discharged home alone scored above suggested cutoff scores on the DRS, indicating generally intact cognitive functioning, whereas those discharged with supervision scored below suggested cutoffs. CONCLUSION: Results emphasize the importance of cognition in the ability to return to completely independent living after medical rehabilitation in geriatric patients.     

Semantic interference in a delayed naming task: Evidence for the response exclusion hypothesis.

In 2 experiments participants named pictures of common objects with superimposed distractor words. In one naming condition, the pictures and words were presented simultaneously on every trial, and participants produced the target response immediately. In the other naming condition, the presentation of the picture preceded the presentation of the distractor by 1,000 ms, and participants delayed production of their naming response until distractor word presentation. Within each naming condition, the distractor words were either semantic category coordinates of the target pictures or unrelated. Orthogonal to this manipulation of semantic relatedness, the frequency of the pictures' names was manipulated. The authors observed semantic interference effects in both the immediate and delayed naming conditions but a frequency effect only in the immediate naming condition. These data indicate that semantic interference can be observed when target picture naming latencies do not reflect the bottleneck at the level of lexical selection. In the context of other findings from the picture-word interference paradigm, the authors interpret these data as supporting the view that the semantic interference effect arises at a postlexical level of processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strategic failure in social interaction: Evidence for expectancy disconfirmation processes.

Two experiments were conducted to test the idea that individuals may fail strategically in order to lower the expectations that others hold for their performances. In a pilot study, participants reported that, when lacking confidence, they would be particularly uncomfortable and anxious with high expectations and would attempt to lower them strategically. In Experiment 1, socially anxious and nonanxious participants were led to believe that an interviewer's high or low expectations were due to a prodigious amount of effort or to very little effort. Socially anxious individuals tended to fail strategically when confronted with high as opposed to low expectations presumably based on a prodigious amount of previous effort. In Experiment 2, individuals high or low in social anxiety were led to believe that an interviewer held either high or low expectations for them. High-anxiety participants, led to believe their initial performance would affect high expections, showed much poorer initial performance relative to all other groups. These findings show that individuals who are particularly doubtful about their ability to perform up to par will sometimes fail strategically at the outset of social interaction as a means to create lower and safer standards. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition of return: Sensitivity and criterion as a function of response time.

[Correction Notice: An erratum for this article was reported in Vol 32(5) of Journal of Experimental Psychology: Human Perception and Performance (see record 2006-12344-017). On page 912, there are typographical errors in Table 1. On page 915, the last line of the left column incorrectly states that the mean response frequencies for Experiment 2 are presented within Table 2. The corrected information for both pages is presented in the erratum.] Inhibition of return (IOR) refers to a mechanism that results in a performance disadvantage typically observed when targets are presented at a location once occupied by a cue. Although the time course of the phenomenon--from the cue to the target--has been well studied, the time course of the effect--from target to response--is unknown. In 2 experiments, the effect of IOR upon sensitivity and response criterion under different levels of speed stress was examined. In go/no-go and choice reaction time tasks, IOR had at least 2 distinct effects on information processing. Early in target processing, before sufficient target information has accrued, there is a bias against responding to cued targets. Later, as target information is allowed to accrue, IOR reduces sensitivity to the target's nonspatial feature. Three accounts relating to the early bias effect of IOR and the late effect of IOR on sensitivity are offered. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The entry point of face recognition: Evidence for face expertise.

Previous studies have shown that experts (e.g., birdwatchers) are as fast to recognize objects at subordinate levels of abstraction (e.g., robin) as they are to recognize the same object at the basic level (e.g., bird). As a test of face expertise, the current study found that adults identify faces more frequently (Experiment 1) and as quickly (Experiment 2) at the subordinate level (e.g., Bill Clinton) as at the basic level (e.g., human). Whereas brief presentation (75 ms) impaired subordinate-level recognition of nonface objects, it did not impair the subordinate level recognition of faces (Experiment 3). Finally, in an identity-matching task, subordinate-level primes facilitated the matching responses of faces but not nonface objects (Experiment 4). Collectively, these results indicate that face expertise, like expert object expertise, promotes a downward shift in recognition to more subordinate levels of abstraction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control of cost in prospective memory: Evidence for spontaneous retrieval processes.

To examine the processes that support prospective remembering, previous research has often examined whether the presence of a prospective memory task slows overall responding on an ongoing task. Although slowed task performance suggests that monitoring is present, this method does not clearly establish whether monitoring is functionally related to prospective memory performance. According to the multiprocess theory (McDaniel & Einstein, 2000), monitoring should be necessary to prospective memory performance with nonfocal cues but not with focal cues. To test this hypothesis, we varied monitoring by presenting items that were related (or unrelated) to the prospective memory task proximal to target events. Notably, whereas monitoring proximal to target events led to a large increase in nonfocal prospective memory performance, focal prospective remembering was high in the absence of monitoring, and monitoring in this condition provided no additional benefits. These results suggest that when monitoring is absent, spontaneous retrieval processes can support focal prospective remembering. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inferences of ability and effort: Evidence for two different processes.

In 2 experiments, 295 undergraduates judged either ability (given performance and effort information) or effort (given performance and ability information) where both the reliability and value of the given information varied. Ss made judgments of IQ (or study time) based on information about the effort a person expended in studying (or IQ), student's performance, or both. Individual differences were found in the judged relationship between ability and effort. Some judged ability and effort to be positively related, whereas others judged ability and effort to be negatively related. These groups also differed in the way information reliability influenced their judgments. The positive group showed effects that agree with either an averaging or correlational model: Higher reliability of one type of information was correlated with a lesser effect of the other type of information. For the negative group, an increase in the reliability of one type of information actually increased the effect of the other type of information, a result that is inconsistent with the averaging model. Both an expectancy-contrast model and a correlational model can account for the results of the negative group. The different effects of information reliability for the 2 groups can be interpreted as evidence of 2 different inference processes. Results show flexibility of human judgment strategies and the need for research considering variables that influence strategy use. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identifying stimuli of different perceptual categories in mixed blocks of trials: Evidence for cost in switching between computational processes.

Responding to stimuli of different perceptual categories is usually faster when the categories are presented isolated from each other, in pure blocks, than when they are presented intermixed, in mixed blocks. According to criterion models, these perceptual mixing costs result from the use of a less conservative response criterion in pure than in mixed blocks. According to alternate processing models, mixing costs result from time-consuming switching in mixed blocks between different computational processes called on by the different perceptual categories. In 5 experiments, participants had to identify number stimuli of different categories. The results showed clear mixing costs whenever these categories differed in their assumed computational processing requirements but not when they differed on features that seemed trivial from a computational viewpoint. The results favor the alternate processing conception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Negative priming in patients with Parkinson's disease: Evidence for a role of the striatum in inhibitory attentional processes.

Patients with Parkinson's disease (PD) and normal controls (NCs) performed a negative priming task. NCs displayed the normal pattern of negative priming in that relative to a control condition they were slower to identify a target within a stimulus array when it had been a distractor in the previous array. PD patients did not display any evidence of negative priming. In contrast, both PD patients and NCs displayed statistically the same level of spatial priming and response repetition cost. Regression analyses indicated that although symptom severity, symptom characteristics, and global cognitive functioning were not reliable predictors of negative priming or spatial priming in PD patients, greater symptom severity and poorer global cognitive functioning were associated with less response repetition cost. The possible role of the striatum in negative priming, spatial priming, and response repetition cost is discussed (PsycINFO Database Record (c) 2010 APA, all rights reserved)