Intensity Generalization: Physiology and Modelling of a Neglected Topic

Ghirlanda, Stefano

doi:10.1006/jtbi.2001.2452

Cited by 16 publications

(28 citation statements)

References 48 publications

(83 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The manner in which generalization increased with fear intensity in Experiment 1 is in line with prior nonhuman animal studies on intensity generalization (Ghirlanda 2002;Ghirlanda and Enquist 2003). When animals are trained to respond to a particular stimulus within a given sensory modality (i.e., a light or noise), there is a strong bias to respond to stimuli along the same dimension that are of greater intensity than the trained CS (i.e., increases in brightness or noise intensity) (Ghirlanda 2002).…”

Section: Relationship To Sensory Forms Of Intradimensional Intensity supporting

confidence: 81%

“…The overall pattern demonstrates an asymmetrical generalization gradient around the reinforced value, consistent with the prediction of an intensity generalization gradient (Ghirlanda and Enquist 2003) but inconsistent with a perceptual feature-based generalization gradient, which would predict a bell-shaped curve around the CS+ value. Saturated monotonic gradients occur when responses evoked by nonconditioned values of greater intensity than the CS+, along a dimension of increasing intensity, do not fall below the CS+ response level (Ghirlanda 2002;Ghirlanda and Enquist 2003). This pattern was consistent across the three blocks of the generalization test (Fig.…”

Section: Generalization Test Scr Analysissupporting

confidence: 59%

“…When animals are trained to respond to a particular stimulus within a given sensory modality (i.e., a light or noise), there is a strong bias to respond to stimuli along the same dimension that are of greater intensity than the trained CS (i.e., increases in brightness or noise intensity) (Ghirlanda 2002). Because there was no difference in the physical intensity of the five stimuli along a sensory dimension (brightness, etc.…”

Section: Relationship To Sensory Forms Of Intradimensional Intensity mentioning

confidence: 99%

See 2 more Smart Citations

Generalization of conditioned fear along a dimension of increasing fear intensity

Dunsmoor¹,

Mitroff²,

LaBar³

2009

Learn. Mem.

184

159

View full text Add to dashboard Cite

The present study investigated the extent to which fear generalization in humans is determined by the amount of fear intensity in nonconditioned stimuli relative to a perceptually similar conditioned stimulus. Stimuli consisted of graded emotionally expressive faces of the same identity morphed between neutral and fearful endpoints. Two experimental groups underwent discriminative fear conditioning between a face stimulus of 55% fear intensity (conditioned stimulus, CS+), reinforced with an electric shock, and a second stimulus that was unreinforced (CSÀ). In Experiment 1 the CSÀ was a relatively neutral face stimulus, while in Experiment 2 the CSÀ was the most fear-intense stimulus. Before and following fear conditioning, skin conductance responses (SCR) were recorded to different morph values along the neutral-to-fear dimension. Both experimental groups showed gradients of generalization following fear conditioning that increased with the fear intensity of the stimulus. In Experiment 1 a peak shift in SCRs extended to the most fear-intense stimulus. In contrast, generalization to the most fear-intense stimulus was reduced in Experiment 2, suggesting that discriminative fear learning procedures can attenuate fear generalization. Together, the findings indicate that fear generalization is broadly tuned and sensitive to the amount of fear intensity in nonconditioned stimuli, but that fear generalization can come under stimulus control. These results reveal a novel form of fear generalization in humans that is not merely based on physical similarity to a conditioned exemplar, and may have implications for understanding generalization processes in anxiety disorders characterized by heightened sensitivity to nonthreatening stimuli.

show abstract

Section: Relationship To Sensory Forms Of Intradimensional Intensity supporting

confidence: 81%

Section: Generalization Test Scr Analysissupporting

confidence: 59%

Section: Relationship To Sensory Forms Of Intradimensional Intensity mentioning

confidence: 99%

See 1 more Smart Citation

Generalization of conditioned fear along a dimension of increasing fear intensity

Dunsmoor¹,

Mitroff²,

LaBar³

2009

Learn. Mem.

184

159

View full text Add to dashboard Cite

show abstract

“…The results can also be derived formally by standard methods of linear algebra and the theory of linear differential equations (Ghirlanda, 2002;Hsiung & Mao, 1998;Simmons, 1974).…”

Section: Resultsmentioning

confidence: 99%

Retrospective Revaluation as Simple Associative Learning.

Ghirlanda

2005

Journal of Experimental Psychology: Animal Behavior Processes

Self Cite

View full text Add to dashboard Cite

Backward blocking, unovershadowing, and backward conditioned inhibition are examples of retrospective revaluation phenomena that have been suggested to involve more than simple associative learning. Models of these phenomena have thus used additional concepts, for example, appealing to attentional effects or more elaborate learning mechanisms. The author shows that a suitable representation of stimuli, paired with a careful analysis of the discriminations faced by animals, leads to an account of these and other phenomena in terms of a simple elemental model of associative learning, with essentially the same learning mechanism as the R. A. Rescorla and A. R. Wagner (1972) model. The author concludes with a discussion of some implications for theories of learning.

show abstract

“…The problem of supernormal stimuli may be approached as pertaining to the more general problem of -generalization‖ or, in the wordings of Ghirlanda and Enquist (2003, 15), the question of -how animals respond to sets of stimuli including familiar and novel stimuli‖, or perhaps more specifically, -how an animal will react to novel stimuli that are somewhat different from familiar ones, to which the animal's reactions are known‖ (Ghirlanda 2002, 389). It is interesting to note that these authors stress the relative neglect of this topic in both recent ethology and psychology, and connect it explicitly to the phenomenon of supernormal stimulation (Ghirlanda 2002;Ghirlanda & Enquist 1999). …”

Section: Different Approaches To Supernormal Stimulus Selectionmentioning

confidence: 99%

Amusing ourselves to death? Superstimuli and the evolutionary social sciences

Block¹,

Laing²

2010

Philosophical Psychology

View full text Add to dashboard Cite

Some evolutionary psychologists claim that humans are good at creating superstimuli, and that many pleasure technologies are detrimental to our reproductive fitness. Most of the evolutionary psychological literature makes use of some version of Lorenz and Tinbergen's largely embryonic conceptual framework to make sense of supernormal stimulation and bias exploitation in humans. However, the early ethological concept -superstimulus‖ was intimately connected to other erstwhile core ethological notions, such as the innate releasing mechanism, sign stimuli and the fixed action pattern, notions that nowadays have, for the most part, been discarded by ethologists. The purpose of this paper is twofold. First, we will reconnect the discussion of superstimuli in humans with more recent theoretical ethological literature on stimulus selection and supernormal stimulation. This will allow for a reconceptualisation of evolutionary psychology's formulation of (supernormal) stimulus selection in terms of domain-specificity and modularity. Second, we will argue that bias exploitation in a cultural species differs substantially from bias exploitation in non-cultural animals. We will explore several of those differences, and explicate why they put important constraints on the use of the superstimulus concept in the evolutionary social sciences.

show abstract

Intensity Generalization: Physiology and Modelling of a Neglected Topic

Cited by 16 publications

References 48 publications

Generalization of conditioned fear along a dimension of increasing fear intensity

Generalization of conditioned fear along a dimension of increasing fear intensity

Retrospective Revaluation as Simple Associative Learning.

Amusing ourselves to death? Superstimuli and the evolutionary social sciences

Contact Info

Product

Resources

About