The acquisition of task-specific productions and modifications of declarative representations in spatial-precuing tasks

The stimulus-response translation stage of human information processing plays a mediating role of relating stimuli to assigned responses. The translation stage has been implicated as the locus of a pattern of differential precuing benefits obtained in spatial-choice tasks (Proctor & Reeve, 1986; Reeve & Proctor, 1985): When pairs of finger responses from the middle and index fingers of each hand are precued, the two leftmost and two rightmost responses show the greatest benefit. This pattern of differential benefits, which occurs regardless of whether the hand placement is adjacent or overlapped, has been attributed to spatially coded representations of the stimulus and response sets in the translation stage. Experiment 1 evaluated whether the mediating role of the translation stage changes with practice. All precued pairs of responses showed equivalent benefits in the last of three sessions. This result indicates that the spatial representations used initially to translate between stimuli and responses have been altered to be more efficient or have been replaced by productions that directly specify fingers. Experiment 2 used a fourth session in which subjects were transferred from the overlapped hand placement to the adjacent placement, or vice versa. For subjects in the former condition, the pattern of differential precuing benefits reappeared in the transfer session. This lack of transfer is consistent with the hypothesis that task-specific productions develop with practice that directly relate stimuli to fingers. For subjects who practiced with the adjacent placement and switched to the overlapped placement, only a nonsignificant tendency existed for the pattern of differential precuing benefits to reappear. This failure of the pattern to reappear could indicate that spatial representations continue to be used to translate between stimuli and responses. Alternatively, as occurs with the overlapped placement, task-specific productions could be acquired that relate stimuli to fingers. If so, the failure of the pattern of differential precuing benefits to reappear would reflect a modification in the representations that are used for translation in the transfer session. Specifically, if subjects were coding the stimulus and response sets on the basis of the distinction between the two hands, as well as the spatial distinction, the differential benefits would be minimized because hand coding should benefit different responses from those benefitted by spatial coding. These alternative explanations were evaluated in Experiment 3 by having subjects who practiced with the adjacent placement switch to a placement in which the hands were crossed completely.(ABSTRACT TRUNCATED AT 400 WORDS)     

Motor set modulates automatic priming effects of uninformative cues

In a series of three experiments, we examined facilitatory and inhibitory effects of uninformative spatial cues in a four-choice reaction time (RT) task that required three different types of responses: detection, reaching, and keypressing. Results revealed a pattern of facilitation and inhibition that strongly depended on response mode: Whereas detection and reaching showed longer RTs for cued than uncued locations (reflecting inhibition of return), keypress responses showed shorter RTs for cued than uncued locations (reflecting automatic response activation). Together, these results provide converging evidence for the Grouping model of precuing effects [Adam, J. J., Hommel, B., & Umiltà, C. (2003). Preparing for perception and action (I): The role of grouping in the response-cuing task. Cognitive Psychology, 46, 302-358; Adam, J. J., Hommel, B., & Umiltà, C. (2005). Preparing for perception and action (II): Automatic and effortful processes in response-cuing. Visual Cognition, 12, 1444-1473].     

The influence of response grouping on free-choice decision making in a response selection task

Previous research has demonstrated an advantage for the preparation of fingers on one hand over the preparation of fingers on two hands, and for the preparation of homologous fingers over that of non-homologous fingers. In the present study, we extended the precuing effects observed with finger responses to response selection under free-choice conditions. Participants were required to choose from a range of possible responses following the presentation of a precue that indicated which response to prepare (go-to precue) or prevent (no-go-to precue). In Experiment 1 the choice was between homologous and non-homologous finger responses on the hand opposite to the precue while in Experiment 2 the choice was between finger responses on the same or different hand to the precue. In the go-to precue condition, the frequency of homologous finger choices was more frequent than non-homologous finger responses. Similarly, participants chose finger responses on the same hand as the precue regardless of whether they were instructed to prepare or prevent the precued response. The hand effect bias was stronger than the finger effect bias. These findings are consistent with the Grouping Model (Adam, Hommel, & Umilta, 2003).     

Response preparation with static versus moving hands

This research tested the response inhibition account of the hand-advantage found in the finger precuing task. According to this account, the advantage of preparing two fingers on one hand (represented in one hemisphere) as opposed to preparing two fingers on two hands (represented in two hemispheres) is due, in part, to a response inhibition process that operates more efficiently within than between hemispheres. In this view, supplying extra activation to both hemispheres by moving the hands should decrease the within-hemisphere inhibition advantage. Twelve participants performed the finger precuing task with static and moving hands. As predicted by the response inhibition account, the hand-advantage, present with the hands at rest, decreased with the hands moving.     

The spatial proximity hypothesis of the hand advantage in spatial precuing tasks : A short note concerning discrepant criterion effects

Within the context of the spatial precuing paradigm a consistent finding is that with the hands placed adjacently precuing of two fingers on the same hand results in faster discrete finger responses than precuing of two fingers on different hands. This phenomenon is known as the ‘hand advantage’. Both Miller (1982) and Reeve and Proctor (1984) considered, and rejected, the ‘spatial proximity’ hypothesis as a possible perceptual explanation of the hand advantage. However, data reported by Miller (1982) and Reeve and Proctor (1984) to discount the spatial proximity hypothesis showed a puzzling inconsistency which weakened the strength of the rejection. In this article I address this inconsistency theoretically and experimentally. I conclude that its origin lies in differential operationalizations of the concept ‘preparation effect’. This conclusion justifies rejection of the spatial proximity hypothesis.     

Preparing fingers within and between hands: Examining the maximal preparation benefit in older age

Previous research has demonstrated an age-related deficit in the preparation of finger responses. A key question is whether the age-related deficit reflects differences in speed of preparation or differences in the maximal preparation benefit that can be attained given sufficiently long preparation intervals. The present study examined this issue by asking a group of younger and older adults to perform the finger-cueing task with four, relatively long, preparation intervals that varied randomly across trials. Reaction time results demonstrated that older adults were deficient in preparing two fingers on two hands at the two shortest preparation intervals, but not at the two longest ones. This outcome suggests that, with randomised preparation intervals, older adults require more time than younger adults to achieve the maximal level of between-hands preparation.     

Specification of movement amplitudes for the left and right hands: evidence for transient parametric coupling from overlapping-task performance

Bimanual coordination tasks suggest transient cross-talk between concurrent specification processes for movements of the left and right hand that vanishes as the time for specification increases. In 2 experiments with overlapping and successive unimanual tasks, the hypothesis of transient coupling was examined for a psychological-refractory-period paradigm. Time for specification was manipulated by varying the delay between first and second signal (Experiment 1) and by precuing the first response (Experiment 2). Participants performed rapid reversal movements of same or different amplitudes with the left and right hands. With different amplitudes, reaction times (RTs) of the second responses were longer than with same amplitudes at short delays, and this disappeared at longer delays in Experiment 1. In Experiment 2, precuing also reduced the difference between RTs of second responses in same-amplitude and different-amplitude trials. These findings are consistent with the hypothesis of transient coupling during amplitude specification obtained with bimanual tasks.     

Characteristics of finger force production during one- and two-hand tasks

Relations among finger forces were studied during one-hand and two-hand isometric maximal force production tasks in right- and left-handers. We particularly focused on the phenomena of force deficit during one-hand multi-finger tasks and of bilateral force deficit during two-hand tasks. Ten healthy subjects (five of them left-handed) performed maximal voluntary force production tasks with different finger combinations involving fingers of one of the hands or of both hands together. In one-hand tasks, finger enslaving (forces produced by fingers that were not instructed to produce force) was larger in the dominant hand, while force deficit (drop in individual finger peak force during multi-finger tasks) showed no differences between the hands. An additional drop in finger forces was seen in two-hand tests (bilateral deficit). The magnitude of the bilateral deficit for a hand was larger for tasks involving fewer fingers within the hand and more fingers in the other hand, with a ceiling effect. Smaller bilateral deficit was seen in tasks involving symmetrical finger combinations. In two-hand tasks that could potentially lead to the generation of large total moments in the frontal plane, the hand that was expected to generate larger moments showed larger bilateral deficit, so that the magnitude of the total moment was reduced. These observations suggest that force deficit within a hand and bilateral deficit have different origins but their effects are combined at a certain level of the multi-finger control hierarchy. Bilateral deficit may display task dependence reflecting, in particular, the principle of minimization of secondary moments. A double-representation, mirror-image hypothesis is suggested to provide a neurophysiological basis for the observed patterns of bilateral deficit.     

Compatibility of precuing and of S-R mapping in choice reactions

This study investigates information processing elicited by precuing a subset of alternatives in a choice reaction task. The aim was to study the influence of some task variables on the effectiveness of precuing, in order to determine the locus of differential precuing effects, in either central decisional processing or in motor programming. Partial advance information (PAI) was given 300 msec in advance of the action signal and it indicated the subset from which the action signal would be chosen. Thus, precuing reduced the number of alternatives. The resulting decrease of reaction time (RT) was assessed under various levels of SR compatibility, response specificity and cue compatibility. Cue compatibility refers to the naturalness of the (spatial) relation between the cue signals and the stimulus-response pairs. This study shows that (a) precuing effectiveness is strongly affected by cue compatibility, and (b) cue compatibility should be viewed as a twofold concept: it refers to the naturalness of the relation of the cue signal, either with action signals or with responses.Experiment 1 compared a naming and a pointing task. Although in both tasks the cue signal was compatible with the cued action signals, the naming task had a lower level of SR compatibility and also a lower level of compatibility between the cue signal and responses. Precuing was highly effective when pointing towards the action signal, but hardly effective when naming ordinal positions. Experiments 2–4, using only a pointing task, showed a decrease of the precuing effect with a decrease of either type of cue compatibility, although cue compatibility with action signals was the strongest factor. Low SR compatibility further decreased the size of the precuing effect caused by low compatibility between cue and action signals. Differential precuing effects did not result from differences in response specificity (i.e., the lack of similarity among the cued responses). It is concluded that precuing and both types of cue compatibility affect the stage of response decision, while no evidence was found for effects on motor programming. Implications are discussed for movement precuing studies that rely on differential precuing effects to discover properties of motor programming.     

Masked response priming in expert typists

In masked priming tasks responses are usually faster when prime and target require identical rather than different responses. Previous research has extensively manipulated the nature and number of response-affording stimuli. However, little is known about the constraints of masked priming regarding the nature and number of response alternatives. The present study explored the limits of masked priming in a six-choice reaction time task, where responses from different fingers of both hands were required. We studied participants that were either experts for the type of response (skilled typists) or novices. Masked primes facilitated responding to targets that required the same response, responses with a different finger of the same hand, and with a homologous finger of the other hand. These effects were modulated by expertise. The results show that masked primes facilitate responding especially for experts in the S–R mapping and with increasing similarity of primed and required response.     

On the advance preparation of discrete finger responses

Most studies that examined the precuing of motor responses have been interpreted as indicating that response specification is a variable-order process. An apparent exception to this conclusion was obtained by Miller (1982) for the preparation of discrete finger responses. Precuing was beneficial only when the precued responses were on the same hand, suggesting that response specification occurs in a fixed order, with hand specified before other aspects of the response. Three experiments examined this discrepant finding for discrete finger responses. Experiment 1 demonstrated that with sufficient time (3 s), all combinations of responses can be equally well prepared. Experiments 2 and 3 showed that the precuing advantage for same-hand responses at shorter precuing intervals is due to strategic and decision factors, not to an ability to prepare these responses more efficiently. Preparation of finger responses, thus, also appears to be variable. This conclusion poses problems for Miller's extension of the precuing procedure to the evaluation of discrete versus continuous models of information processing.     

Integration of hand and finger location in external spatial coordinates for tactile localization

Tactile stimulus location is automatically transformed from somatotopic into external spatial coordinates, rendering information about the location of touch in three-dimensional space. This process is referred to as tactile remapping. Whereas remapping seems to occur automatically for the hands and feet, the fingers may constitute an exception in that some studies have implied purely somatotopic coding of touch to the fingers. When participants judge the order of two tactile stimuli, they often err when the stimulated body parts (usually the two hands) are crossed, presumably because somatotopic and external coordinates are in conflict in crossed postures. Using this task, we investigated, first, whether the fingers are unlike other limbs with regard to spatial coding, by testing whether crossing effects, indicative of external coding, were observable when stimulating two fingers, either on the same or on different hands. Second, we investigated the interaction of hand and finger posture in tactile localization of finger stimuli. Crossing effects emerged when fingers and hands were crossed, suggesting external coding for all body parts. Crossing effects were larger when both hand and finger were located in the hemifield opposite to their body side, and smaller when only hand or finger lay in the opposite hemifield. We suggest that tactile location is estimated by integrating the external location of all relevant body parts, here of a finger and its belonging hand, and that such integrative coding may represent a general principle for body part processing as well as for tool use.     

Endogenous visuospatial precuing effects as a function of age and task demands

This experiment examined the effects of age on processing resource capacity using an endogenous visuospatial precuing task and four levels of resource demands. Younger and older adults made speeded two-choice responses to dim and bright targets that required a line-orientation or a lexical decision. An arrow preceding target onset served as an attentional cue to affect the spatial distribution of resources. It provided accurate information about the target’s location on most trials and inaccurate or neutral information on the remaining trials. Although older adults were slower than younger adults under all conditions and were more affected by the resource demand manipulations, they exhibited a pattern of precuing effects across conditions that was similar to that of the younger adults. Results are consistent with the idea that the visuospatial attention system remains relatively unaffected by aging. However, the data speak against the idea that capacity reduction is the primary contributor to age-related slowing.     

Same-hand and different-hand finger pairings in two-choice reaction time: presence or absence of response competition?

Several two-choice reaction time experiments have compared conditions in which the two possible responses were from the same hand (same-hand pairing) or from different hands (different-hand pairing). Studies that used only the two relevant fingers on response keys reported shorter reaction times for the different-hand pairing. In other studies, two additional but irrelevant fingers were also in contact with response keys. These fingers were irrelevant in the sense that they never were required to respond. With this procedure, equivalent reaction times were found between same-hand and different-hand pairings. Reeve and Proctor (1988) recently have argued that using only two fingers results in response competition between the two fingers from the same hand, yielding shorter reaction times for the different-hand pairing condition. In contrast, when four fingers are placed on response keys, response competition should be absent for both the same-hand and the different-hand pairing conditions, resulting in equivalent reaction times. In the present work, reaction times associated with the same-hand pairing condition remained unchanged, irrespective of the number of fingers positioned on keys. In the different-hand pairing condition, reaction times were found to be longer when four fingers were used than when only two fingers rested on response keys. Thus, when four fingers are placed on keys, response competition appears to be present rather than absent. Other results showed that the response competition found in the different-hand pairing condition decreases with practice.     

Proactive inhibitory control of emotional distractors: Evidence for the benefit of precuing emotional distractors

The present study investigated the role of proactive inhibitory control in processing emotional distractors by examining the benefit of precuing the following emotional distractor. In Experiments 1A and 1B, an emotional flanker task was used while schematic emotional faces were presented as targets and distractors. We found the benefit of precuing the emotional distractor. In Experiment 2, the precue could not predict the following emotional distractor. The benefit of precuing the emotional distractor diminished, suggesting that the benefit was not due to reactive inhibition of the precued distractor. In Experiments 3A and 3B, an emotional Stroop task was used while schematic emotional faces were presented as distractors. The benefit of precuing the emotional distractors was observed when these distractors were emotional faces but not observed when the distractors were scrambled faces. These findings suggested that the benefit of precuing the emotional distractors operates at the emotional level.     

Expanding the tactual field of view

Can tactual information be acquired simultaneously by several different fingers? Blind and sighted Ss were asked to scan vertical displays of braille (consisting of either one or two dots) with the index and middle fingers on each hand-using one, two, or four fingers at the same time. Stimuli were recognized most rapidly when the displays were scanned by two fingers on different hands and least rapidly when two fingers on the same hand were used; performance was similar with one finger and with four fingers. The results indicated some parallel perceptual processing of the inputs to the two hands and mutual interference in processing inputs from fingers on the same hand.     

Selecting mapping rules and responses in mixed compatibility four-choice tasks

Four-choice reaction tasks with a mixture of compatible and incompatible mappings were used to examine implications of the views that response selection occurs (a) in two stages (selection of the appropriate mapping rule, followed by application of the rule) and (b) by means of a second, direct route when the mappings for all possible stimuli are known to be compatible. All experiments showed, consistent with the two-stage view, that responses were faster and compatibility effects smaller when the mapping distinction corresponded to the left-right or inner-outer locations for the stimulus-response ensemble than when it did not. Moreover, precuing benefits tended to be larger when the cued responses had the same mapping than when they did not. There was an added benefit when both precued responses were compatible, rather than incompatible, consistent with the view that selection between compatible responses can proceed along a direct route. Received: 9 July 1997 / Accepted: 5 February 1998     

Influence of practice on response-selection and response-implementation processes involved in the response-interference effect

In a choice reaction-time task, the response-interference effect is an increase in reaction times when the two possible responses are from the same hand compared to when the two possible responses are from different hands [Psychonomic Science 2 (1965) 55-56; Human Motor Control, Academic Press, San Diego, CA, 1991]. Although the influence of practice on other reaction-time effects (i.e., the complexity effect and precuing) has been examined, research evaluating the influence of practice on the response-interference effect is limited. Therefore, two experiments were conducted to determine the influence of practice on the response-interference effect. In Experiment 1, a bilateral transfer task was used to assess the influence of practice on the response-selection processes associated with the response-interference effect. The practice results indicated decreased reaction times, but did not influence the response-interference effect. In Experiment 2, a priming task was used to assess the influence of practice on response-implementation processes associated with the response-interference effect. The reaction time results indicated a change in the response-interference effect. The results of these two experiments suggest that with only two fingers on response keys, practice alters the mechanical constraints affecting the response-implementation processes and thereby decreases the response-interference effect.     

The effects of spatial uncertainty and cue predictability on visual orienting in children

Visual orienting was studied using a task that required participants to respond to stimuli at various locations that were either accurately or inaccurately cued. Orienting abilities of children ages 6 to 8 years, and young adults (21 years) were tested under conditions of spatial uncertainty (i.e., multiple possible target locations), and variable cue predictability (i.e., variable proportion of validly cued targets). The results indicate that children orient their attentional resources automatically to abrupt visual onsets, and do so under conditions when it is not beneficial to overall performance. Adults, on the other hand, are able to control their orienting in such a way that it is limited to conditions where it improves their task efficiency. There appears to be developmental change in the ability to assess the utility of a location cue and/or to moderate responses in accordance with the utility of a cue. This finding is discussed in terms of the development of attentional control and inhibitory processes in children.