Vibrotactual choice reaction time, tactile receptor systems and ideomotor compatibility

When the vibrations allow for anticipating the force to be produced: an extend to Pfister et al. (2014)

According to the ideomotor theory, action selection is done by the mental anticipation of its perceptual consequences. If the distal information processed mainly by vision and hearing are considered essential for the representation of the action, the proximal information processed by the sense of touch and proprioception is of less importance. Recent works seem to show the opposite. Nevertheless, it is necessary to complete these results by offering a situation, more ecological, where response and effect can occur on the same effector. So, the goal of our work was to implement a more relevant spatial correspondence because to touch is not the same action that to hear or to see. To do so, participants pressed a specific key after the presentation of a stimulus. The key vibrated depending on the pressure exerted on it. In a compatible condition, high pressure on a key triggered a high vibration, while in an incompatible condition high pressure triggered a low vibration on the same effectors. As expected, the response times were faster in the compatible condition than the incompatible condition. This means that proximal information participates actively in the selection of action.

Hick's law for choice reaction time: A review

In 1952, W. E. Hick published an article in the Quarterly Journal of Experimental Psychology, "On the rate of gain of information." It played a seminal role in the cognitive revolution and established one of the few widely acknowledged laws in psychology, relating choice reaction time to the number of stimulus-response alternatives (or amount of uncertainty) in a task. We review the historical context in which Hick conducted his study and describe his experiments and theoretical analyses. We discuss the article's immediate impact on researchers, as well as challenges to and shortcomings of Hick's law and his analysis, including effects of stimulus-response compatibility, practice, very large set sizes and sequential dependencies. Contemporary modeling developments are also described in detail. Perhaps most impressive about Hick's law is that it continues to spawn research efforts to the present and that it is regarded as a fundamental law of interface design for human-computer interaction using technologies that did not exist at the time of Hick's research.

An optimal adjustment procedure to minimize experiment time in decisions with multiple alternatives

Decisions between multiple alternatives typically conform to Hick's Law: Mean response time increases log-linearly with the number of choice alternatives. We recently demonstrated context effects in Hick's Law, showing that patterns of response latency and choice accuracy were different for easy versus difficult blocks. The context effect explained previously observed discrepancies in error rate data and provided a new challenge for theoretical accounts of multialternative choice. In the present article, we propose a novel approach to modeling context effects that can be applied to any account that models the speed-accuracy trade-off. The core element of the approach is "optimality" in the way an experimental participant might define it: minimizing the total time spent in the experiment, without making too many errors. We show how this approach can be included in an existing Bayesian model of choice and highlight its ability to fit previous data as well as to predict novel empirical context effects. The model is shown to provide better quantitative fits than a more flexible heuristic account.

Context effects in multi-alternative decision making: empirical data and a Bayesian model

For decisions between many alternatives, the benchmark result is Hick's Law: that response time increases log-linearly with the number of choice alternatives. Even when Hick's Law is observed for response times, divergent results have been observed for error rates-sometimes error rates increase with the number of choice alternatives, and sometimes they are constant. We provide evidence from two experiments that error rates are mostly independent of the number of choice alternatives, unless context effects induce participants to trade speed for accuracy across conditions. Error rate data have previously been used to discriminate between competing theoretical accounts of Hick's Law, and our results question the validity of those conclusions. We show that a previously dismissed optimal observer model might provide a parsimonious account of both response time and error rate data. The model suggests that people approximate Bayesian inference in multi-alternative choice, except for some perceptual limitations.

A memory-based model of Hick's law

We propose and evaluate a memory-based model of Hick's law, the approximately linear increase in choice reaction time with the logarithm of set size (the number of stimulus-response alternatives). According to the model, Hick's law reflects a combination of associative interference during retrieval from declarative memory and occasional savings for stimulus-response repetitions due to non-retrieval. Fits to existing data sets show that the model accounts for the basic set-size effect, changes in the set-size effect with practice, and stimulus-response repetition effects that challenge the information-theoretic view of Hick's law. We derive the model's prediction of an interaction between set size, stimulus fan (the number of responses associated with a particular stimulus), and stimulus-response transition, which is subsequently tested and confirmed in two experiments. Collectively, the results support the core structure of the model and its explanation of Hick's law in terms of basic memory effects.

Are spatial responses to visuospatial stimuli and spoken responses to auditory letters ideomotor-compatible tasks? Examination of set-size effects on dual-task interference

Previous studies have paired a visual-manual Task 1 with an auditory-vocal Task 2 to evaluate whether the psychological refractory period (PRP) effect is eliminated with two ideomotor-compatible tasks (for which stimuli resemble the response feedback). The present study varied the number of stimulus-response alternatives for Task 1 in three experiments to determine whether set-size and PRP effects were absent, as would be expected if the tasks bypass limited-capacity response-selection processes. In Experiments 1 and 2, the visual-manual task was used as Task 1, with lever-movement and keypress responses, respectively. In Experiment 3, the auditory-vocal task was used as Task 1 and the visual-manual task as Task 2. A significant lengthening of reaction time for 4 vs. 2 alternatives was found for the visual-manual Task 1 and the Task 2 PRP effect in Experiments 1 and 2, suggesting that the visual-manual task is not ideomotor compatible. Neither effect of set size was significant for the auditory-vocal Task 1 in Experiment 3, but there was still a Task 2 PRP effect. Our results imply that neither version of the visual-manual task is ideomotor compatible; other considerations suggest that the auditory-vocal task may also still require response selection.

Visually guided, aimed movements can be unaffected by stimulus–response uncertainty

Response times generally increase linearly with the logarithm of the number of potential stimulus-response alternatives (e.g., Hick's law). The ubiquity and theoretical importance of this generalization make exceptions particularly interesting. Recently, Kveraga et al. (Exp Brain Res 146:307, 2002) added a third to the two previously known exceptions, demonstrating that saccade latencies were unaffected by stimulus-response uncertainty. They suggest that visually guided saccades are exceptional, because these movements can be automatically selected using a privileged pathway: the topographically organized regions in superior colliculus that convert spatially coded visual activity into spatially coded motor commands. We report that visually guided, aimed hand movements also are unaffected by both stimulus-response uncertainty and stimulus-response repetition. A second experiment demonstrated that this lack of an uncertainty effect persists for equiluminant stimuli. This result suggests that posterior parietal cortex is not the privileged pathway eliminating stimulus-response uncertainty for hand movements. Because hand movements are not guided by mechanisms in the superior colliculus, our results cast doubt on the privileged-pathway hypothesis, at least for hand movements. Instead, the absence of stimulus-response uncertainty may occur only in tasks that do not require the stimulus to be associated with a response effector and that have high stimulus-response compatibility.

Effects of stimulus-response uncertainty on saccades to near-threshold targets

Kveraga et al. (2002, Exp Brain Res 146(3):307-14) reported that saccade latencies are immune to the effects of stimulus-response uncertainty and constitute one of the few response systems that violate Hick's law. Similar effects have been reported for keypresses triggered by vibrations of the fingertips, but robust uncertainty effects were subsequently revealed using weak, low-frequency vibrations (Ten Hoopen et al. 1982, Acta Psychol 50:143-157). We wondered whether immunity of saccadic responses would demonstrate a similar intensity-dependency and therefore re-examined the effects of response entropy on saccade latencies using near-threshold visual stimuli. Saccadic latencies remained independent of stimulus-response uncertainty, indicating that saccadic motor programming is unaffected by the duration of the target detection process.

Contributions of sensation and perception studies to the design of artificial environments

It is argued that knowledge of cognitive psychology, and hence also of sensation and perception, one of its branches, is indispensable when one aims at improving our artificial environment. Four examples of sensation and perception studies are described. Firstly, an experiment was discussed to design a postal code format that can be used accurately in terms of the capacity of short-term visual memory. The second example describes a perceptual conflict between visual and bodily (kinesthetic/proprioceptive) sensations that arises as a result of wrongly designing buildings. In the third example it is shown that vibrotactual displays should present frequencies that trigger the Pacinian system in the skin if people have to make quick and accurate decisions. Finally, a study of a simple acoustic orientation system that can promote indoor travel and activity by blind people was described.

Spatial stimulus-response compatibility and coding of tactile motor events: influence of distance between stimulated and responding body parts, spatial complexity of the task and sex of subject

We studied spatial stimulus response compatibility in the somatosensory modality by instructing 16 men and 16 women to press a key using the left or the right thumb in response to a nonnoxious electric stimulation delivered either to the left or to the right little finger or, in different blocks, to the left or to the right malleolar region. The task was performed in compatible (stimulus and key-response on the same side of the corporeal midline) and in incompatible conditions (stimulus and key-response on opposite sides of the corporeal midline). In Exp. 1 subjects were tested while keeping their limbs in anatomic position; in Exp. 2 subjects performed the task while keeping the left upper and lower limbs on the right side and the right limbs on the left side of the bodily midline (crossed position). The compatibility effect was observed in both experiments and was higher for stimuli delivered to the little finger than to the malleolar region. This suggests that the cost of inhibiting compatible responses is maximal when stimulated and responding body parts are contiguous. Moreover, in the spatially most demanding task (Exp. 2) men outperformed women for both speed and accuracy suggesting a sex related specialisation in the spatial processing of somatosensory information.

Pigeon reaction time, Hick's law, and intelligence

Pigeons' choice reaction times (RTs) increased as a linear function of log2 number of potential target stimuli (Experiments 1-3), as would be predicted by Hick's law. The values of intercepts and slopes decreased with training (Experiments 2 and 3) and with differential reinforcement of short RTs under percentile reinforcement contingencies (Experiment 3). RT functions obtained from human subjects were also consistent with Hick's law, but slopes for pigeons were significantly lower than those for humans (Experiments 4 and 5). These results extend the generality of Hick's law to pigeons but are inconsistent with Jensen's claim that the parameters of the Hick function are related to intelligence.