Anticipatory nausea in cancer patients receiving chemotherapy: Classical conditioning etiology and therapeutical implications

The delivery of cytotoxic drugs in cancer treatment is often accompanied by posttreatment side effects (e.g., nausea). Moreover, there is evidence that cancer patients are at risk to develop these side effects in anticipation of chemotherapy (i.e., anticipatory nausea [AN]). AN can be explained as the result of a classical conditioning process with the cytotoxic drug as the unconditioned stimulus (US). Stimuli paired with the US (e.g., smells, tastes) can become conditioned stimuli (CSs) eliciting AN as the conditioned response (CR). The present study was conducted to test whether AN shows characteristics of a CR. Fifty-five ambulatory cancer patients were asked to record nine kinds of physical symptoms (e.g., nausea, vomiting, sweating) on time-scheduled symptom lists: after an infusion (indicating posttreatment symptoms) and prior to their next infusion (indicating anticipatory symptoms). Each measurement period covered a maximum of 48 hours. AN was reported by ten patients (18.08%). Data revealed (a) a statistically significant association between posttreatment nausea and vomiting, respectively, and AN; (b) the occurrence of AN increased with drug emetogenity (i.e., US-intensity); and (c) the duration of AN increased with temporal proximity to the infusion. The results support the conditioning model. Thus, it is proposed to prevent AN by classical conditioning techniques (e.g., overshadowing).     

Differential context effects between sweet tastes and smells

"Sweet" smells and tastes are perceptually similar, and physiological data indicate some commonality of central processing. However, sweet tastes and sweet smells do not provide interchangeable contexts in psychophysical experiments. The same sweet tastes are perceived as less intense when stronger sweet tastes are present, and they are perceived as more intense when weaker sweet tastes are present, as with sweet smells. However, complementary sets of sweet tastes and smells (e.g., weak sweet tastes, strong sweet smells) do not eliminate these differential context effects (DCEs). The present experiments examined, first, whether DCEs between sweet tastes and smells arise because of differences between odors and tastes in the way that sweetness scales with intensity as concentration rises, and, second, whether DCEs may be smaller for sweet tastes and smells, when contrasted with sweet tastes and nonsweet smells. The findings were clear: DCEs were consistently present, suggesting they are independent of perceptual similarity. These results imply that DCEs are probably not psychological in origin or centrally based; rather, they may have a subcortical locus.     

Verifying different-modality properties for concepts produces switching costs

According to perceptual symbol systems, sensorimotor simulations underlie the representation of concepts. It follows that sensorimotor phenomena should arise in conceptual processing. Previous studies have shown that switching from one modality to another during perceptual processing incurs a processing cost. If perceptual simulation underlies conceptual processing, then verifying the properties of concepts should exhibit a switching cost as well. For example, verifying a property in the auditory modality (e.g., BLENDER-loud) should be slower after verifying a property in a different modality (e.g., CRANBERRIES-tart) than after verifying a property in the same modality (e.g., LEAVES-rustling). Only words were presented to subjects, and there were no instructions to use imagery. Nevertheless, switching modalities incurred a cost, analogous to the cost of switching modalities in perception. A second experiment showed that this effect was not due to associative priming between properties in the same modality. These results support the hypothesis that perceptual simulation underlies conceptual processing.     

Stress and cytokine-elicited neuroendocrine and neurotransmitter sensitization: implications for depressive illness

Stressful events, by their effects on neurotransmitter and neuroendocrine processes, are thought to favor the development or exacerbation of depressive illness. In as much as immunological challenge, may provoke stressor-like neuroendocrine and central neurochemical changes, the view was offered that immune activation essentially acts like a stressor and may contribute to the evolution of affective illness. In this respect, viral and bacterial infections appear to influence behavioral/metabolic (e.g. fever, anorexia, somnolence) and neurotransmitter functioning through the release of cytokines, which act as messengers between the immune system and brain. The present report provides a brief overview of the neurochemical consequences of proinflammatory cytokine treatments, particularly the actions of interleukin (IL)-1beta and tumor necrosis factor-alpha. As well, synergy with psychogenic and neurogenic stressors are described, as are data showing that cytokines, like stressors, may have time-dependent proactive (sensitization) effects, so that reexposure to the treatments greatly augments hypothalamic-pituitary-adrenal activity, as well as central neurochemical changes. Indeed, the neurotransmitter alterations are not restricted to hypothalamic nuclei, but occur in several extrahypothalamic sites, including various limbic regions. It is suggested that by virtue of these neurochemical changes, cytokines may have both immediate and proactive effects on mood states.     

Reactions to Medical Diagnosis: The Role of Illness Stereotypes

Two studies were conducted to explore the role of illness stereotypes in appraisals of health threat. The results of Study 1 indicated that a substantial proportion of questionnaire respondents believed that high blood pressure (BP) is associated with positive personal characteristics (e.g., persistence) whereas a smaller proportion believed that high BP is associated with negative characteristics. In addition, more favorable stereotypes were correlated with lower ratings of the seriousness of high BP. Study 2 examined the effects of experimentally induced illness stereotypes on the health-related judgments of subjects who received false feedback on a test of their BP. The results revealed a significant effect of illness stereotypes on health-threat appraisals of high BP. Subjects who were led to believe that high BP was associated with achievement and competence perceived high BP as a less serious threat to health than did subjects who believed high BP was associated with less desirable traits. In addition, subjects given high BP readings reported fewer symptoms they were told were associated with high BP when the disorder was associated with negative characteristics. The results demonstrate the importance of illness stereotypes in appraisals of health threats, symptom reporting, and reactions to medical diagnosis.     

ListChecker Pro 1.2: A program designed to facilitate creating word lists using the University of South Florida word association norms

Various areas of research (e.g., memory, metamemory, visual word recognition, associative priming) rely on the careful construction of reliable word lists. ListChecker Pro 1.2 is a computer program that accesses the University of South Florida word association norms (Nelson, McEvoy, & Schreiber, 1998, 2004) to report characteristics of words (e.g., frequency, concreteness), as well as direct and indirect associative relationships (e.g., shared associates, mediators). The present article presents the input requirements, menu options, and output obtained by ListChecker Pro 1.2. In addition, a randomly selected list of words from the associative versus semantic priming literature was submitted to ListChecker Pro 1.2 to demonstrate how seemingly unrelated words can be associated. The zipped file containing the program and database can be downloaded from www .eakinmemorylab.psychology.msstate.edu.     

Physical illness and symptoms of depression among elderly outpatients.

Elderly outpatients were assessed to clarify relations between symptoms of depression and physical illness, disability, pain, and selected psychosocial variables. Three types of assessments were made: (a) medical evaluations by physicians, (b) self-reported symptoms of depression and physical health, and (c) demographic and psychosocial data relating to participants' life circumstances. Both objective (physician-rated illness symptoms) and subjective (self-reported health, activity restriction, and use of pain medications) indicators of health accounted for independent variance in symptoms of depression. After controlling for these factors, additional variance was explained by health-related concerns (e.g., health care expenses, service needs), social support, and "other worries" (e.g., feeling useless, becoming a burden to others).     

Does jugde activate COURT? Transposed-letter similarity effects in masked associative priming

Transposed-letter (TL) nonwords (e.g., jugde) can be easily misperceived as words, a fact that is somewhat inconsistent with the letter-position-coding schemes employed by most current models of visual word recognition. To examine this issue further, we conducted four masked semantic/associative priming experiments, using a lexical decision task. In Experiment 1, the related primes could be words, TL-internal nonwords, or replacement-letter (RL) nonwords (e.g., judge, jugde, or judpe, respectively; the target would be COURT). Relative to an unrelated condition, masked TL-internal primes produced a significant semantic/associative priming effect, an effect that was only slightly smaller than the priming effect for word primes. No effect, however, was observed for RL-nonword primes. In Experiment 2, the TL-nonword primes were created by switching the two final letters of the primes (e.g., judeg). The results again showed a semantic/associative priming effect for word primes, but not for TL-final nonword primes or for RL-nonword primes. Experiment 3 replicated the associative/semantic priming effect for TL-internal nonword primes, with, again, no effect for TL-final nonword primes. Finally, Experiment 4 again failed to yield a priming effect for TL-final nonword primes. The implications of these results for the choice of a letter-position-coding scheme in visual word recognition models are discussed.     

The role of similarity in human associative learning

In 2 experiments, humans received sequences of patterns that were similar (AX-->BX, AY-->BY, AZ-->BZ) or dissimilar (CX-->DY, CY-->DZ, CZ-->DX). The patterns were portrayed as bugs that could be eliminated with 2 insecticide sprays (red or blue). Either spray eliminated bugs with Features A and C, and participants learned by trial and error to use one spray (e.g., red) to eliminate bugs with Feature B and the other spray (e.g., blue) to eliminate those with Feature D. In Experiment 1, participants' spray choice for bugs with Feature A came to match that used to eliminate bugs with Feature B, but there was no such associative transfer between Features C and D. That is, similarity promoted associative transfer of responding between paired patterns when the features used to manipulate similarity (i.e., X, Y, and Z) were irrelevant. In Experiment 2, in which X, Y, and Z were relevant to the solution of configural discrimination, similarity hindered such associative transfer. These results complement those found in pigeons (R. A. Rescorla & D. J. Gillan, 1980) and indicate that similarity should not be accorded independent status as a principle of associative learning.     

Asymmetries in cue competition in forward and backward blocking designs: Further evidence for causal model theory

A hallmark feature of elemental associative learning theories is that multiple cues compete for associative strength when presented with an outcome. Cue competition effects have been observed in humans, both in forward and in backward blocking procedures (e.g., Shanks, 1985) and are often interpreted as evidence for an associative account of human causal learning (e.g., Shanks & Dickinson, 1987). Waldmann and Holyoak (1992), however, demonstrated that cue competition only occurs in predictive, and not diagnostic, learning paradigms. While unexplainable from an associative perspective, this asymmetry readily follows from structural considerations of causal model theory. In this paper, we show that causal models determine the extent of cue competition not only in forward but also in backward blocking designs. Implications for associative and inferential accounts of causal learning are discussed.     

Associative and strategic components of episodic memory: a life-span dissociation

The authors investigated the strategic component (i.e., elaboration and organization of episodic features) and the associative component (i.e., binding processes) of episodic memory and their interactions in 4 age groups (10-12, 13-15, 20-25, and 70-75 years of age). On the basis of behavioral and neural evidence, the authors hypothesized that the two components are functionally related but follow different life-span gradients. In a fully crossed design, age differences in recognition memory for single words versus word pairs (associative demand manipulation) were examined under instructions that emphasized item, pair, or elaborative-pair encoding (strategy manipulation). As predicted, the results showed that the strategic and associative components follow different life-span trajectories. Relative to younger adults, children's difficulties in episodic memory primarily reflected lower levels of strategic functioning. In contrast, older adults showed impairments in both strategic and associative components. The authors conclude that the comparison of strategic and associative components of episodic memory across the life span helps to delineate the two components' unique and interactive contributions to episodic memory performance.     

The gulf war: Distressful reactions to scud missiles attacks

This study investigated the relationships among coping strategies, trait anxiety and distressful reactions (State anxiety and fears and symptoms) of Israeli civilians under missile attack during the 1991 Gulf war. During the war sixty-six subjects (46 females and 20 males) completed a questionnaire that measured their distressful reactions and included fears in various situations (e.g., during the night, in the sealed room) and various symptoms (e.g., sleep disturbances, sensitivity to noise). In addition each subject completed the Coping Inventory for Stressful Situations (CISS, Endler & Parker, 1990a), a multidimensional self-report measure of coping which measures three major coping strategies: task-oriented, emotion-oriented and avoidance-oriented. Subjects also completed the State and Trait anxiety scales of the Endler Multidimensional Anxiety Scales (EMAS, Endler, Edwards, & Vitelli, 1991). The state anxiety scales measure two components of the individual's state anxiety, cognitive worry and autonomic emotional reactions. The trait anxiety scales measure the individual's predisposition to experience anxiety in four different situations: social evaluation, physical danger, ambiguous situations and daily routines. The results showed that individuals who used emotion-oriented coping more frequently, experienced more state anxiety and symptoms and fears, (i.e., experienced greater distress) during the war. Task-oriented and avoidance-oriented coping were not related to the distressful reactions. It was further found that subjects high on physical danger trait anxiety and social evaluation trait anxiety experienced greater fears and more symptoms (i.e., experienced greater distress) during the war. Persons high on social evaluation trait anxiety also experienced great cognitive-worry state anxiety. The results are discussed within the framework of the multidimensional model of stress, anxiety and coping (Endler, 1988; Endler & Parker, 1990a, 1990b) and the special characteristics of the Gulf war situation.     

Retrospective Revaluation and Inhibitory Associations: Does Perceptual Learning Modulate our Perception of the Contingencies Between Events?

The reported experiments seek to reconcile the conflict between proposed explanations of retrospective revaluation of contingency judgements in experiments with humans (e.g. Dickinson & Burke, 1996) and those of a perceptual learning phenomenon discovered in rats (Espinet, Iraola, Bennett, &Mackintosh, 1995). The experiments employ a medical diagnosis scenario, in which subjects are asked to judge whether particular symptoms signal the presence or absence of a fictitious disease. In Experiment 1, following alternating exposure to pairs of symptoms, AX and BX, subjects were informed that symptom A was predictive of illness. As a result of this training, subjects rated symptom B as predictive of the absence of the illness. In Experiment 2, a possible mechanism behind this effect was considered. In particular, it was established that pre-exposure in which the AX pair reliably preceded the BX pair produced the same pattern of results as those shown in Experiment 1. In contrast, when the order of pairs was reversed, so that BX reliably preceded AX, the reduction in ratings for symptom B was not obtained. Several extant associative theories are discussed, but none are found to account adequately for this pattern of results. To overcome these inadequacies, a parsimonious theory is suggested that explains all the effects observed in these experiments.     

Distinguishing familiarity from fluency for the compound word pair effect in associative recognition

We examined whether processing fluency contributes to associative recognition of unitized pre-experimental associations. In Experiments 1A and 1B, we minimized perceptual fluency by presenting each word of pairs on separate screens at both study and test, yet the compound word (CW) effect (i.e., hit and false-alarm rates greater for CW pairs with no difference in discrimination) did not reduce. In Experiments 2A and 2B, conceptual fluency was examined by comparing transparent (e.g., hand bag) and opaque (e.g., rag time) CW pairs in lexical decision and associative recognition tasks. Lexical decision was faster for transparent CWs (Experiment 2A) but in associative recognition, the CW effect did not differ by CW pair type (Experiment 2B). In Experiments 3A and 3B, we examined whether priming that increases processing fluency would influence the CW effect. In Experiment 3A, CW and non-compound word pairs were preceded with matched and mismatched primes at test in an associative recognition task. In Experiment 3B, only transparent and opaque CW pairs were presented. Results showed that presenting matched versus mismatched primes at test did not influence the CW effect. The CW effect in yes-no associative recognition is due to reliance on enhanced familiarity of unitized CW pairs.     

Cognitive arithmetic: Evidence for obligatory activation of arithmetic facts

In two experiments, obligatory activation of arithmetic facts resulted in interference on a simple number-matching task. Subjects were required to verify the presence of a probe number (e.g., 5) in a previously presented pair (e.g., 5+1). Items for which the probe was the sum of the initial pair (e.g., 5+1 and 6) were rejected more slowly than items for which the probe was not the sum (e.g., 5+1 and 3), and this effect was largest at stimulus onset asynchronies of less than 180 msec between the number pair and the probe. The results are consistent with the notion that arithmetic knowledge is represented in an associative network and accessed by means of spreading activation.     

Translation and associative priming with cross-lingual pseudohomophones: evidence for nonselective phonological activation in bilinguals

Using a lexical-decision task performed by Dutch-English bilinguals, the author showed that the recognition of visually presented first language (L1; e.g., touw) and second language (L2; e.g., back) targets is facilitated by L2 and L1 masked primes, respectively, which are pseudohomophones (roap and ruch) of the target's translation equivalent (rope and rug). Moreover, recognition of L2 targets (e.g., church) was also facilitated by L1 pseudohomophones (pous) of related words (paus [pope]). Contrastingly, no priming was observed for L1 targets (e.g., been [leg]) and L2 pseudohomophone associative primes (knea). Finally, the author found that an L2 target word (e.g., corner) is facilitated by a more frequent L2 (intralingual) homophone (e.g., hook) of its L1 translation equivalent (hoek). These findings strongly suggest language-independent activation of phonological representations in bilinguals and are compatible with the temporal delay assumption of the bilingual interactive activation plus model (A. Dijkstra & W. Van Heuven, 2002).     

Associative history affects the associative change undergone by both presented and absent cues in human causal learning

R. A. Rescorla (2000) noted that a number of influential theories of associative learning do not take the associative history of cues (i.e., the prior training that they have received) into account when calculating the associative change undergone by those cues. The authors tested this assumption in a human causal learning paradigm and found associative history to be an important determinant of the learning undergone by cues that are presented on a trial. Moreover, associative history was also found to influence the amount of retrospective revaluation undergone by absent cues. These findings conflict with models of causal learning in which the associative change undergone by an element of a cue compound is governed by a summed error term (e.g., R. A. Rescorla & A. R. Wagner, 1972).     

Prototypes and personal templates: collective wisdom and individual differences

This article concerns individual differences in the associative meaning of psychological concepts. Associative meaning may be assessed with prototype methodology, which yields a list of features of the concept ordered according to their rated importance. Our theory concerns individual differences in a concept's associative meaning: A personal template reveals a person's idiosyncratic associative meaning. It is possible to assess the degree to which a personal template matches the corresponding prototype. The theory distinguishes among three types of concepts. One type, for example, specifies a particular behavior to be predicted, for example, a person who is likely to commit suicide, and features of the prototype would include predictors of suicidal behavior. According to the theory, the most prototypical features are (under specifiable conditions) valid predictors, and people with a strong template-to-prototype match possess more valid knowledge about the concept than do people with a weak template-to-prototype match. Other types of concepts cannot be validated (e.g., those describing subjective experiences). In that case, a strong template-to-prototype match does not reflect a person's degree of valid knowledge. The authors provide three applications of the theory.     

Associative and phonological priming effects after letter search on the prime

Responses to target words typically are faster and more accurate after associatively related primes (e.g., "orange-juice") than after unrelated primes (e.g., "glue-juice"). This priming effect has been used as an index of semantic activation, and its elimination often is cited as evidence against semantic access. When participants are asked to perform a letter search on the prime, associative priming typically is eliminated, but repetition and morphological priming remain. It is possible that priming survives letter search when it arises from activity in codes that are represented before semantics. This experiment examined associative and phonological priming to determine whether priming from phonologically related rhymes would remain after letter search (e.g., "moose-juice"; rhyming items were orthographically dissimilar). When participants read the primes, equivalent associative and phonological priming effects were obtained; both effects were eliminated after letter search. The impact of letter search on semantic and phonological access and implications for the structural arrangement of lexical and semantic memory are discussed.