Abstract stimuli associated with threat through conditioning cannot be detected preattentively

Studies of anxiety suggest that threat stimuli can be identified preattentively, but this conclusion is questionable because of possible low-level perceptual confounds. Two experiments used visual search tasks in which abstract shapes were conditioned to carry neutral or negative valence. Experiment 1 found generally faster responses to threat-associated abstract stimuli but no evidence that they were detected preattentively, irrespective of trait anxiety level. A similar pattern was found in Experiment 2, in which individuals high in snake or spider fear showed no evidence of preattentive detection of abstract stimuli associated with their feared object. In contrast, implicit behavioral measures showed significant effects of conditioning, demonstrating that targets associated with threat were negatively evaluated in these experiments.     

Pavlovian conditional stimuli cannot always be defined solely in physical terms

Twenty-four university students received differential Pavlovian conditioning with two colored stimuli separately accompanied by shock, and two other colored stimuli separately presented without shock. The reinforced and nonreinforced pairs of stimuli both contained complementary elements. After differentiation between the reinforced and nonreinforced elements was established, the complementary pairs were each additively mixed, (i.e., presented at the same time and in the same locus), producing two identical white compounds (established by pilot study). The subjects’ skin-conductance responses to the two compounds showed that their different conditioning histories did not result in different responses. Rather, a simple declining function was obtained, resembling habituation or extinction. It was concluded that the definition of the conditional stimulus as a physical event is inappropriate in studies in which physically different stimuli may result in identical internal processes (or phenomenologic experiences)—for example, in additive color mixture.     

Method of constant stimuli: Recalculations show that response-frequency equalization cannot fit the data

The bias found in the method of constant stimuli has been attributed either to an adaptation-level effect or to a response bias. Restle and Levison presented data purported to show that the result could not be explained by response frequency equalization, the best available response-bias theory. Erlebacher and Sekuler elaborated their theory and calculated a version of the model that would fit the main experimental result, but chose an erroneously large value for the standard deviation of their model. Their model does not produce an acceptable fit to the data, and therefore does not successfully compete with the adaptation-level model.     

Neural computations that underlie decisions about sensory stimuli

Decision-making behavior has been studied extensively, but the neurophysiological mechanisms responsible for this remarkable cognitive ability are just beginning to be understood. Here we propose neural computations that can account for the formation of categorical decisions about sensory stimuli by accumulating information over time into a single quantity: the logarithm of the likelihood ratio favoring one alternative over another. We also review electrophysio-logical studies that have identified brain structures that may be involved in computing this sort of decision variable. The ideas presented constitute a framework for understanding how and where perceptual decisions are formed in the brain.     

Why a scientific realist cannot be a functionalist

According to functionalism, mental state types consist solely in relations to inputs, outputs, and other mental states. I argue that two central claims of a prominent and plausible type of scientific realism conflict with the functionalist position. These claims are that natural kinds in a mature science are not reducible to natural kinds in any other, and that all dispositional features of natural kinds can be explained at the type-level. These claims, when applied to psychology, have the consequence that at least some mental state types consist not merely in relations to inputs, outputs, and other mental states, but also in nonrelational properties that play a role in explaining functional relations. Consequently, a scientific realist of the sort I describe must reject functionalism.     

On the development of procedural knowledge

Amnesic patients demonstrate by their performance on a serial reaction time task that they learned a repeating spatial sequence despite their lack of awareness of the repetition (Nissen & Bullemer, 1987). In the experiments reported here, we investigated this form of procedural learning in normal subjects. A subgroup of subjects showed substantial procedural learning of the sequence in the absence of explicit declarative knowledge of it. Their ability to generate the sequence was effectively at chance and showed no savings in learning. Additional amounts of training increased both procedural and declarative knowledge of the sequence. Development of knowledge in one system seems not to depend on knowledge in the other. Procedural learning in this situation is neither solely perceptual nor solely motor. The learning shows minimal transfer to a situation employing the same motor sequence.     

Sensory and conceptual representations in memory: Motor images that cannot be imaged

Summary The paper argues for a distinction between sensory-and conceptual-information storage in the human information-processing system. Conceptual information is characterized as meaningful and symbolic, while sensory information may exist in modality-bound form. Furthermore, it is assumed that sensory information does not contribute to conscious remembering and can be used only in data-driven process reptitions, which can be accompanied by a kind of vague or intuitive feeling. Accordingly, pure top-down and willingly controlled processing, such as free recall, should not have any access to sensory data. Empirical results from different research areas and from two experiments conducted by the authors are presented in this article to support these theoretical distinctions. The experiments were designed to separate a sensory-motor and a conceptual component in memory for two-digit numbers and two-letter items, when parts of the numbers or items were imaged or drawn on a tablet. The results of free recall and recognition are discussed in a theoretical framework which distinguishes sensory and conceptual information in memory.     

Effects of age on searching for and enumerating targets that cannot be detected efficiently

We investigated the effects of old age on search, subitizing, and counting of difficult-to-find targets. In Experiment 1, young and older adults enumerated targets (Os) with and without distractors (Qs). Without distractors, the usual subitization-counting function occurred in both groups, with the same subitization span of 3.3 items. Subitization disappeared with distractors; older adults were slowed more overall by their presence but enumeration rates were not slowed by ageing either with or without distractors. In contrast, search rates for a single target (O among Qs) were twice as slow for older as for young adults. Experiment 2 tested and ruled out one account of age-equivalent serial enumeration based on the need to subvocalize numbers as items are enumerated. Alternative explanations based on the specific task differences between detecting and enumerating stimuli are discussed.     

Effects of knowledge that attributions will be observed by others

The current study was conducted to determine if attribution statements would be affected by subjects' knowledge that their attributions of success or failure would be observed by an opposite-sex peer. At the time subjects recorded their attributions, half of them anticipated that their attributions would soon be observed in their presence by an opposite-sex peer, while the other half recorded their attributions anonymously. Results indicated that attributions of success and failure were affected by the social context. Observed subjects evidenced less tendency to attribute their failure to low ability than did nonobserved subjects. Subjects who succeeded on an identity-relevant task reported higher ability attributions under observation conditions than under nonobservation conditions. Observed subjects evidenced significantly greater willingness to attribute failure to lack of effort than did nonobserved subjects. For a task intended to be of minimal relevance to subjects' identities, nonobserved subjects attributed failure to task difficulty to a significantly greater degree than did observed subjects. Results were discussed in relation to Bradley's contention that self-serving biases in attribution can usefully be conceptualized as strategic self-presentations.     

Inferences about mechanisms that mediate pattern and flicker sensitivity

Attention, Perception, & Psychophysics - Visual sensitivity to a flickering, sinusoidal grating was assessed in multiple sclerosis patients and control observers. It was found that losses in...     

To be or not to be a galaprock: Preschoolers' intuitions about the importance of knowledge and action for pretending

Can someone pretend to be a galaprock without knowing what a galaprock is? Do children recognize that such knowledge is required for pretending? Three studies focusing on the relations among action, knowledge and pretending suggest that children have this understanding by age 4 years. In Study 1, 4‐year‐olds and adults willingly pretended to be moving and unmoving objects but had trouble pretending to be objects that were difficult to represent physically. In Study 2, 3‐ and 4‐year‐olds claimed they could not pretend to be an unknown thing, justifying their refusals with mentalistic language indicating their ignorance of the object or its typical actions. In Study 3, 3‐ to 5‐year‐olds predicted that other children who have knowledge of an object unfamiliar to the subjects themselves can nevertheless pretend to be it, whereas those lacking that knowledge cannot. The results add support to the growing literature showing that preschoolers conceptualize pretense as involving mental activity.     

On the assessment of procedural knowledge: From problem spaces to knowledge spaces

By generalizing and completing the work initiated by Stefanutti and Albert (2003, Journal of Universal Computer Science, 9, 1455), this article provides the mathematical foundations of a theoretical approach whose primary goal is to construct a bridge between problem solving, as initially conceived by Newell and Simon (1972, Human problem solving. Englewood Cliffs, NJ: Prentice-Hall.), and knowledge assessment (Doignon and Falmagne, 1985, International Journal of Man-Machine Studies, 23, 175; Doignon and Falmagne, 1999, Knowledge spaces. Berlin, Germany: Springer-Verlag.; Falmagne et al., 2013, Knowledge spaces: Applications in education. New York, NY: Springer-Verlag; Falmagne and Doignon, 2011, Learning spaces: Interdisciplinary applied mathematics. Berlin, Germany: Springer-Verlag.). It is shown that the collection of all possible knowledge states for a given problem space is a learning space. An algorithm for deriving a learning space from a problem space is illustrated. As an example, the algorithm is used to derive the learning space of a neuropsychological test whose problem space is well known: the Tower of London (TOL; Shallice, 1982, Philosophical Transactions of the Royal Society of London B: Biological Sciences, 298, 199). The derived learning space could then be used for adaptively assessing individual planning skills with the TOL.     

Acquisition of knowledge about spatial location: Assessing the generality of the mechanism of learning

A selection of studies in the last 20 years is reviewed. These studies show basic Pavlovian phenomena in the spatial domain (like blocking, overshadowing, latent inhibition, and perceptual learning) with nonhuman subjects, specifically with rats, both in the radial maze and in the circular pool. The generality of these phenomena with respect to other species and to other spatial preparations is also discussed. The conclusion is that the mechanism responsible for the acquisition of knowledge about spatial location seems to be associative in nature.     

Grouping of stimuli in pattern recognition as a function of age

Two groups of subjects aged 20-40 and 40-60 years learnt identifying responses to a set of eight patterns. The groups did not differ in rate of learning, but an analysis of confusions between patterns revealed systematic differences in the extent to which rules underlying the construction of patterns were used in recognizing them as members of sub-sets before identifying responses were mastered.     

The use of procedural knowledge in simple addition and subtraction problems

In a first experiment, adults were asked to solve one-digit additions, subtractions and multiplications. When the sign appeared 150 ms before the operands, addition and subtraction were solved faster than when the sign and the operands appeared simultaneously on screen. This priming effect was not observed for multiplication problems. A second experiment replicates these results on addition and multiplication and, moreover, shows that the priming effect in addition is observed for all problems, including very small ones such as 4+3. In fact, the only problems that were not primed by the addition sign were tie problems, which confirms that they have a special status in memory. Taken together, these results suggest that abstract procedures are pre-activated by the addition and subtraction signs and that these procedures are consequently used by adults to solve the problems. No such procedures would be pre-activated for multiplication, which are then most probably solved by retrieval of the result from memory. Moreover, while obviously two different strategies were used by individuals in order to solve addition and multiplication, solution times were similar when the problems were presented in their whole. These results, which question most of the conclusions of the current literature, support Anderson's model (1982) and Baroody's assumptions (1983) on the existence of compacted procedures that could be as fast as retrievals.