Continuous priming effects on discrete response choices

When primed by backward-masked, target-like stimuli, discrete responses (e.g. button presses) to simple visual targets can be slower when prime and target match (compatible) than when they do not (incompatible). The current study investigated the nature of the stimulus–response mapping underlying this negative compatibility effect (NCE). Discrete left–right responses to arrow targets were primed with arrows oriented in one of 16 directions. Responses were either a standard button press or a 10 cm movement on a graphics tablet. Both tasks showed an identical NCE; importantly, reaction times in both tasks decreased smoothly as the angular distance between prime and target increased (i.e. as compatibility decreased), with the largest NCE evident between the extreme cases (prime-target distances of 0° and 180°). Primes exerted an effect on the required response in proportion to the amount of overlap (reflecting population vector coding). The mapping between the priming stimulus and response is continuous, not categorical.     

Available response choices affect localization of sound

Successful replication of an experiment by Butler and Humanski (1992) showed that listeners are able to proficiently localize sources on a lateral vertical plane on the basis of interaural differences alone. When a lateral horizontal array was included in the test setup, that finding was replicated only for a broadband signal interacting with the pinna, not for ones (lowpass and pure tone) providing only interaural differences. Cross-plane errors conforming to “cones of confusion” were observed for those latter sounds. In a second experiment, response options were made more unconstrained, which clarified the nature of the cross-plane confusions. Lowpass signals from lateral vertical plane sources tend to be heard at or close to the horizon. Measurement of cue values needs to take account of the response options available to listeners, as well as signal properties.     

The transitivity of choices between different response requirements

This experiment tested the transitivity of hens' choices between response requirements differing in both form and number. In a concurrent second-order schedule procedure, 6 hens chose between two alternatives by making either key-peck or door-push responses. The reinforcement rates on the two alternatives remained constant and equal throughout conditions, but the number of responses (i.e., key pecks or door pushes) required on each alternative was varied by changing the second-order (fixed-ratio) requirements. The preferences obtained from two pairings of response requirements allowed prediction of the preferences expected in a third pairing. No intransitivities were found, implying that the response requirements lie on a common unitary scale of value. For response-based measures, the obtained preferences varied evenly around perfect, multiplicative prediction, and all satisfied strong transitivity, implying an underlying interval scale of value. For time-based measures, only moderate transitivity was satisfied, implying only an ordinal scale of value. Time-based measures were confounded with the differing times taken to complete each response requirement. The existence of such scales indicates that direct comparisons of different response requirements may be possible.     

Individual commitment to risky and conservative choices as a determinant of shifts in group decisions1

The consistently positive relationship between initial riskiness and perceived influence obtained in past work led us to speculate that (1) the deliberative effort involved in making a choice increases with its riskiness, as a result (2) individuals who select a risky course of action will be more committed to their choice than conservative individuals, and (3) the former will be more influential in group decisions. The following support was obtained for these conjectures When individuals had to select a reaction time interval to beat, those who were risky, that is, who selected a short interval, were more confident in having chosen wisely, were less likely to feel they might change their choice given the opportunity, and took longer to make their choice than those who were conservative, that is, who selected a long interval The first two of these measures were assumed to reflect commitment to the choice, and the third was taken as a rough indication of the amount of effort involved in choosing A group decision was also made regarding the reaction time interval It tended to be riskier than that preferred by the average individual prior to the decision if the riskiest member was more committed and/or expended more effort in choosing than his partners, on the other hand, it tended to be more conservative than the average prior preference if the most conservative member was more committed and or expended more effort     

Choices and preferences: Evidence from implicit choices and response times

We present a new experimental paradigm where choice-induced preference change is measured for alternatives which are never compared directly, but rather confronted with other alternatives in a way which keeps choices predictable without exogenously manipulating them. This implicit-choice design improves on the free-choice paradigm, avoiding the recently criticized selection bias. Rating and ranking spreads in two experiments show that preference-based choices feed back into and alter preferences even if choices are not directly among similarly evaluated alternatives. In agreement with recent brain-imaging evidence, response time measurements for direct choice pairs in our experiments indicate that reappraisal processes are already triggered during decision making, with larger post-choice spreads (sharper attitude change) being associated to quicker decisions.     

Category label and response location shifts in category learning

The category shift literature suggests that rule-based classification, an important form of explicit learning, is mediated by two separate learned associations: a stimulus-to-label association that associates stimuli and category labels, and a label-to-response association that associates category labels and responses. Three experiments investigate whether information–integration classification, an important form of implicit learning, is also mediated by two separate learned associations. Participants were trained on a rule-based or an information–integration categorization task and then the association between stimulus and category label, or between category label and response location was altered. For rule-based categories, and in line with previous research, breaking the association between stimulus and category label caused more interference than breaking the association between category label and response location. However, no differences in recovery rate emerged. For information–integration categories, breaking the association between stimulus and category label caused more interference and led to greater recovery than breaking the association between category label and response location. These results provide evidence that information–integration category learning is mediated by separate stimulus-to-label and label-to-response associations. Implications for the neurobiological basis of these two learned associations are discussed.     

An integrated model of choices and response times in absolute identification

Recent theoretical developments in the field of absolute identification have stressed differences between relative and absolute processes, that is, whether stimulus magnitudes are judged relative to a shorter term context provided by recently presented stimuli or a longer term context provided by the entire set of stimuli. The authors developed a model (SAMBA: selective attention, mapping, and ballistic accumulation) that integrates shorter and longer term memory processes and accounts for both the choices made and the associated response time distributions, including sequential effects in each. The model's predictions arise as a consequence of its architecture and require estimation of only a few parameters with values that are consistent across numerous data sets. The authors show that SAMBA provides a quantitative account of benchmark choice phenomena in classical absolute identification experiments and in contemporary data involving both choice and response time.     

Effects of pre-trial response requirements on self-control choices by rats and pigeons

Parallel experiments with rats and pigeons examined whether the size of a pre-trial ratio requirement would affect choices in a self-control situation. In different conditions, either 1 response or 40 responses were required before each trial. In the first half of each experiment, an adjusting-ratio schedule was used, in which subjects could choose a fixed-ratio schedule leading to a small reinforcer, or an adjusting-ratio schedule leading to a larger reinforcer. The size of the adjusting ratio requirement was increased and decreased over trials based on the subject's responses, in order to estimate an indifference point-a ratio at which the two alternatives were chosen about equally often. The second half of each experiment used an adjusting-delay procedure-fixed and adjusting delays to the small and large reinforcers were used instead of ratio requirements. In some conditions, particularly with the reinforcer delays, the rats had consistently longer adjusting delays with the larger pre-trial ratios, reflecting a greater tendency to choose the larger, delayed reinforcer when more responding was required to reach the choice point. No consistent effects of the pre-trial ratio were found for the pigeons in any of the conditions. These results may indicate that rats are more sensitive to the long-term reinforcement rates of the two alternatives, or they may result from a shallower temporal discounting rate for rats than for pigeons, a difference that has been observed in previous studies.     

What do differences between own,admired, and attributed choices have to do with group induced shifts in choice

Two studies examined certain discrepancies which have been considered important evidence in support of interpersonal comparison (value-adherence) explanations of group induced shifts in choice. These are (a) the differences between a person's own choice and the choice he predicts others would make and (b) the difference between the former and the choice he admires. Findings from the first study indicate that own choices are more extreme than those a person predicts others would make because he is more certain and confident about the former than the latter, not because he wishes to appear to outdo others as interpersonal comparison theories of choice-shift effect would have it. The second study strongly suggests that extreme choices are admired not because they display maximal adherence to a social ideal but because they imply that the person's solution to a problem involving choice is well-founded, that he has persuasive reasons for the choice. On the whole the evidence bodes well for explanations of choice-shift effects based on persuasive argumentation and poorly for those relying on interpersonal comparison processes.     

Ontogenetic and phylogenetic shifts in the cognitive representation of the conditioned response

The retention of the conditioned response was tested in a retroactive interference paradigm using subjects from kindergarten, Grades 3 and 6, and college. The conditioned stimuli (CS) were either a tone or light, and the unconditioned stimuli (US) were vibratory tactual stimulations delivered to either the right or left index finger which produced a withdrawal response. Original AB learning consisted of pairing one of the CSs with one of the USs (e.g., tone-left). Interpolated CD learning consisted of pairing the other CS with the other US (e.g., light-right). When the first stimulus was presented alone to test for retroactive interference, the college students gave the response associated with it during original learning, the B response, but the kindergartners and third graders gave the D response, which was never associated with the CS during training. A second experiment used avoidance conditioning instructions and replicated these results while including rest-control and AD groups. These data suggest that what is learned by children in simple conditioning paradigms is different than what is learned by adults in the same paradigms. The results are discussed in terms of the following two hypotheses: (a) Russian theories of conditioning and extensions of Tighe and Tighe's and Kendler's theories of the development of perception and discrimination learning in children, and (b) theories of development of separability in perceptual development.     

Effects of response time deadlines on adults' strategy choices for simple addition

In this investigation of adults' solution strategies for simple arithmetic, participants solved addition problems (e.g., 2 + 3, 8 + 7) under fast and slow response deadlines: The participants were instructed either to respond before a 750-msec warning beep, or to wait for a 2,500-msec beep before responding. After each trial, they indicated whether they had solved the problem by direct memory retrieval or by using a procedural strategy (e.g., counting, transformation). It was predicted that the fast deadline condition should curtail the use of procedural strategies, which generally are slower than direct retrieval. Furthermore, this deadline effect should be exaggerated for numerically larger problems because procedural strategies are especially slow for the larger problems. As predicted, we observed a deadline x size interaction whereby the fast deadline increased reported use of retrieval, especially for large problems. The results confirm that reported use of direct retrieval decreases systematically with elapsed time, and they provide additional evidence that young, educated adults rely substantially on procedural strategies even for simple addition.     

Extremity shifts,risk shifts and attitude shifts after group discussion

Moscovici and Zavalloni (1969) suggest that both risk shifts and attitude shifts after group discussion are examples of a general group tendency to polarize opinions. In the present experiment, using both attitude and risk items, group discussion did not make individual opinions more extreme; only the group average became more extreme. This group extremity increase was not simply a more general way of conceptualizing the directional shifts in attitude and risk; group extremity increase appeared to be an effect of discussion that was independent of the risk and attitude shifts. Also, subjects in the co-working pretest of the standard risk-shift paradigm were found to be less extreme and more ‘agreeing’ than pretest subjects who were truly alone. This co-working/alone difference persisted after discussion and was not related to group extremity increase. On both attitude and risk items, group extremity increase was strongly correlated with group opinion convergence. It is argued from this correlation that group extremity increase may be an effect of some aspect of conformity influence.     

Evolution and human choices

The postmodern world seems to have conclusively lost faith in the heady promises of human emancipation through rational understanding that have pervaded the Western world since the time of the Enlightenment. As the end of the millennium approaches and the evidence of man‐made environmental degradation accumulates nihilism and malaise color the future. This article argues that a clear understanding of both evolutionary forces and human consciousness permits to formulate a guardedly optimistic alternative view. It is advanced that the very sense of despair current circumstances have created may trigger a move toward a new form of psycho‐functional adaptation, simultaneously constituting a first instance of “conscious evolution” and fulfilling the progressive promise intrinsic in the full use of our rational faculties.     

Cosmological choices

Present physics is a mix of theories of time, logic, and matter. These may have a common origin in a unitary quantum cosmology founded on process alone. A quantum theory of sets, or something like it, is helpful for such a cosmology, and one is constructed by adding superposition to a slightly reformulated classical set theory. There is an elementary or atomic process in such theories. The size of its characteristic time is estimated from the mass spectrum, although this gives a much larger time than is usually accepted. In a discussion of the foundations of quantum theory, the problem of the collapsing state-vector is attributed to statism, the ideology, alien to quantum theory, that the system under study has a state. The origin of metrical and gauge structure is considered. Using von Neumann's work on the lattices of algebras, we may represent almost any gauge structure by enlarging the ring of c-numbers of quantum theory beyond the complex (or quaternion) field. Ultimately the gauge structure and c-numbers may express a transport relation defined by the discrete network of the world.This material is based upon work supported by the National Science Foundation under Grant No. PHY-8007921.     

Perceptual learning in contrast detection: presence and cost of shifts in response criteria

Contemporary theoretical accounts of perceptual learning typically assume that observers are either unbiased or stably biased across the course of learning. However, standard methods for estimating thresholds, as they are typically used, do not allow this assumption to be tested. We present an approach that allows for this test specific to perceptual learning for contrast detection. We show that reliable decreases in detection thresholds and increases in hit rates are not uniformly accompanied by reliable increases in sensitivity (d′), but are regularly accompanied by reliable liberal shifts in response criteria (c). In addition, we estimate the extent to which sensitivity could have increased in the absence of these liberal shifts. The results pose a challenge to the assumption that perceptual learning has limited or no impact on response criteria.     

Not all choices are created equal: Task-relevant choices enhance motor learning compared to task-irrelevant choices

Lewthwaite et al. (2015) reported that the learning benefits of exercising choice (i.e., their self-controlled condition) are not restricted to task-relevant features (e.g., feedback). They found that choosing one’s golf ball color (Exp. 1) or choosing which of two tasks to perform at a later time plus which of two artworks to hang (Exp. 2) resulted in better retention than did being denied these same choices (i.e., yoked condition). The researchers concluded that the learning benefits derived from choice, whether irrelevant or relevant to the to-be-learned task, are predominantly motivational because choice is intrinsically rewarding and satisfies basic psychological needs. However, the absence of a group that made task-relevant choices and the lack of psychological measures significantly weakened their conclusions. Here, we investigated how task-relevant and task-irrelevant choices affect motor-skill learning. Participants practiced a spatiotemporal motor task in either a task-relevant group (choice over feedback schedule), a task-irrelevant group (choice over the color of an arm-wrap plus game selection), or a no-choice group. The results showed significantly greater learning in the task-relevant group than in both the task-irrelevant and no-choice groups, who did not differ significantly. Critically, these learning differences were not attributed to differences in perceptions of competence or autonomy, but instead to superior error-estimation abilities. These results challenge the perspective that motivational influences are the root cause of self-controlled learning advantages. Instead, the findings add to the growing evidence highlighting that the informational value gained from task-relevant choices makes a greater relative contribution to these advantages than motivational influences do.     

Lesbian motherhood and genetic choices

Rhonda, a physician, and Clara, a registered nurse, have been lovers for the past 7 years. Both women are in their 30s, in good health, and financially stable. Clara has contacted Dr. Robinson, a highly regarded obstetrician and geneticist, with an unusual request. Clara is seeking to become pregnant by means of in vitro fertilization (IVF) with an embryo transfer (ET) technology. She proposes being implanted with ova harvested from her partner, Rhonda, and fertilized in vitro with donor sperm from a local medical-school sperm bank. Dr. Robinson explains the relatively low success rate involved in IVF and ET techniques and suggests artificial insemination of Clara's own ova. Clara and Rhonda understand the low success rates but are undeterred. Their mutual goal is not merely to have a child but to share in the maternity of their children. What ethical issues are raised by the plan Clara and Rhonda propose? What are Dr. Robinson's ethical responsibilities with respect to the request by Clara and Rhonda?     

Change seeking and shock choices

According to sensation-seeking theory, people have characteristic optimal levels of arousal and are motivated to vary stimulus input to reach that level. Self-report studies suggest that seeking changes in stimulation may be one way people control their level of stimulation. The present study tested this hypothesis with a controlled laboratory experiment, using the shock choice procedure. Subjects were asked to choose between a 3-s shock to the wrist immediately or a 1-s shock to the wrist delayed 30 s. “Change seeking” was measured as the number of changes, from trial to trial, between immediate and delayed choices. In order to test change seeking at two levels of arousal, half the subjects were relaxed before making shock choices and half were not. As predicted, subjects who scored high on two subscales of sensation seeking, Boredom Susceptibility and Experience Seeking, made more shock-choice changes during the relaxed condition than subjects who scored low on these two subscales.