Watch what you type: The role of visual feedback from the screen and hands in skilled typewriting

Attention, Perception, & Psychophysics - Skilled typing is controlled by two hierarchically structured processing loops (Logan & Crump, 2011): The outer loop, which produces words,...     

Judgments of perceptual groups: reliability and sensitivity to stimulus transformation

The reliability of subjects' judgments of the groups present in dot patterns and the sensitivity of those judgments to stimulus transformation were assessed. The subjects indicated the groups that they saw within random dot patterns, and each judgment was compared with those of other subjects and with their own judgments for related presentations. Within subjects, each pattern appeared in an initial presentation, an identical repetition, and a transformed state (a rotation or a change in scale). Within-subjects judgments were more reliable than between-subjects judgments. An interpretation of within-subjects results was made in relation to predictions made by a formal algorithm of grouping by proximity (the CODE algorithm), which assumes that grouping by proximity is invariant over transformations such as rotations or changes in scale. A slight cost to transforming the patterns was found. The implications for CODE and for using grouping judgments as data are discussed.     

When it hurts to be misled: A Stroop-like effect in a simple addition production task

In four experiments, subjects saw simple addition equations (e.g., 3 + 4 = 9) and produced the sums while ignoring the presented answer. If the presented answer was false, subjects took longer to produce the sum, as compared with when the presented answer was true (Experiment 1), when there was no answer presented (blanks; Experiment 2), when a letter was presented (Experiment 3), and when a symbol was presented (Experiment 4). The results suggest that subjects were unable to ignore the presented answers, which raises problems for theories of arithmetic verification (i.e., deciding whether 3 + 4 = 9 is true or false) that claim that subjects verify equations by first producing the sum and then comparing the produced sum with the presented answer. Our results are more compatible with theories that claim that in verification and production, an arithmetic knowledge base is used in different ways.     

Modeling task switching without switching tasks: a short-term priming account of explicitly cued performance

Switch costs in task switching are commonly attributed to an executive control process of task-set reconfiguration, particularly in studies involving the explicit task-cuing procedure. The authors propose an alternative account of explicitly cued performance that is based on 2 mechanisms: priming of cue encoding from residual activation of cues in short-term memory and compound cue retrieval of responses from long-term memory. Their short-term priming account explains the repeated cue encoding benefit, switch cost, reduction in switch cost with preparation time, and other effects. The authors develop a mathematical model of their priming account and fit it to data from 3 experiments, demonstrating that a set of basic psychological processes can produce several effects--including putative switch costs--without switching tasks.     

Horse-race model simulations of the stop-signal procedure

In the stop-signal paradigm, subjects perform a standard two-choice reaction task in which, occasionally and unpredictably, a stop-signal is presented requiring the inhibition of the response to the choice signal. The stop-signal paradigm has been successfully applied to assess the ability to inhibit under a wide range of experimental conditions and in various populations. The current study presents a set of evidence-based guidelines for using the stop-signal paradigm. The evidence was derived from a series of simulations aimed at (a) examining the effects of experimental design features on inhibition indices, and (b) testing the assumptions of the horse-race model that underlies the stop-signal paradigm. The simulations indicate that, under most conditions, the latency, but not variability, of response inhibition can be reliably estimated.     

Animal Rights and Animal Experiments: An Interest-Based Approach

This paper examines whether non-human animals have a moral right not to be experimented upon. It adopts a Razian conception of rights, whereby an individual possesses a right if an interest of that individual is sufficient to impose a duty on another. To ascertain whether animals have a right not to be experimented on, three interests are examined which might found such a right: the interest in not suffering, the interest in staying alive, and the interest in being free. It is argued that while the first two of these interests are sufficient to ground animal rights against being killed and made to suffer by experiments, the interest in freedom does not ground a general animal right not to be used in experimentation. Winner of the second annual Res Publica Postgraduate Essay Prize, 2006.     

On the importance of being first: Serial order effects in the interaction between action plans and ongoing actions

When we plan sequences of actions, we must hold some elements of the sequence in working memory (WM) while we execute others. Research shows that execution of an action can be delayed if it partly overlaps (vs. does not overlap) with another action plan maintained in WM (partial repetition cost). However, it is not known whether all features of the action maintained in WM interfere equally with current actions. Most serial models of memory and action assume that interference will be equal, because all action features in the sequence should be activated to an equal degree in parallel; others assume that action features earlier in the sequence will interfere more than those later in the sequence, because earlier features will be more active. Using a partial repetition paradigm, this study examined whether serial position of action features in action sequences maintained in WM have an influence on current actions. Two stimulus events occurred in a sequence, and participants planned and maintained an action sequence to the first event (action A) in WM while executing a speeded response to the second event (action B). Results showed delayed execution of action B when it matched the first feature in the action A sequence (partial repetition cost), but not when it matched the last feature. These findings suggest that serial order is represented in the action plan prior to response execution, consistent with models that assume that serial order is represented by a primacy gradient of parallel feature activation prior to action execution.     

Disentangling the belief in God and cognitive rigidity/flexibility components of religiosity to predict racial and value-violating prejudice: A Post-Critical Belief Scale analysis

Past research indicates that being religious is associated with prejudice toward racial and value-violating out-groups. However, this past research treated religiosity as a unidimensional construct without taking into account how different components of religiosity—belief in a higher power and the rigidity/flexibility of religious beliefs—are associated with measures of prejudice. Two studies examined the relationship between these two components of religiosity, as measured by the Post-Critical Beliefs Scale, and racial (African Americans, Arabs) and value-violating prejudices (atheists, gay men). As the flexibility of religious beliefs increased (literal vs. symbolic dimension), attitudes toward racial and value-violating out-groups became more positive (Study 1). As belief in God strengthened (exclusion vs. inclusion of transcendence dimension), attitudes toward value-violating out-groups became more negative. Study 2 demonstrated that these two components of religiosity fully mediated the relationship between general religiosity and prejudice toward African Americans, Arabs, and gay men and partially mediated the relationship between religiosity and prejudice toward atheists. Results are discussed in light of reexamining the conclusion that simply being religious is associated with prejudice.