Smelling more or less: Investigating the olfactory experience of the domestic dog

The performance of tracking dogs and drug-, disease-, and explosives-detection dogs is a testament to trained dogs’ olfactory acuity. The olfactory experience of an untrained dog, by contrast, has not been well documented. In the current research we begin to remedy that by testing untrained pet dogs’ olfactory perception of quantity. While previous research found that dogs could discriminate visible quantities of more or less food (Prato-Previde, Marshall-Pescini, & Valsecchi, 2008), our results find that, by contrast, companion dogs do not reliably discriminate quantities when the food can be smelled but not seen. Sixty-one percent of dogs (39 of 64), given a choice between closed plates with one and five morsels of food, approached plates with the larger quantity: not significantly more than approached plates with the lesser quantity (binomial, p = .169). We did find that during dogs’ initial investigation of both food amounts, subjects gave more attention to the plate containing the larger quantity (binomial, p < 0.001). In a second condition, we replicated, with closed plates, Prato-Previde et al.’s (2008) finding that owner interest in a plate holding a lesser quantity of food reliably leads dogs to approach that plate (binomial, p < 0.001). Though research has demonstrated dogs’ preference for a larger amount of food ( Ward & Smuts, 2007), in a third condition testing the effect of adding a strong odor to a visibly larger food quantity, we found that the addition of odor often reversed that preference (44/69 dogs; p < .03). Finally, we consider the methodological implications of this work on future dog cognition studies.     

Olfactory Comfort: Smelling a Partner's Clothing During Periods of Separation1

We demonstrate for the first time that most women, and some men, deliberately smell their partners' clothing when they are apart. We asked undergraduate men and women who were, or who had ever been, in a committed heterosexual relationship if they had ever slept with an article of a partner's clothing or deliberately smelled a partner's clothing during periods of separation. Both men and women reported that smelling an absent partner's clothing made them feel happy, comfortable, and secure. We suggest that olfactory comfort is a significant component of attachment and is likely to involve family members other than partners.     

Modulating the masked congruence priming effect with the hands and the mouth

The authors report a series of experiments in which they use the masked congruence priming paradigm to investigate the processing of masked primes in the manual and verbal response modalities. In the manual response modality, they found that masked incongruent primes produced interference relative to both congruent and neutral primes. This finding, which replicates the standard finding in the masked congruence priming literature, is presumed to reflect the conflict that arises between two incompatible responses and, thus, to index the extent of processing of the masked prime. Somewhat surprisingly, when participants were asked to respond verbally in the same task, masked incongruent primes no longer produced interference, but masked congruent primes produced facilitation. These findings are surprising because they suggest that the processing of nonconsciously perceived primes extends to the response level in the manual, but not verbal, response modality. The authors propose that the modulation of the masked congruence priming effect by response modality is due to verbal, but not manual, responses being mediated by the lexical-phonological production system.     

Smelling what was there: Acquired olfactory percepts are resistant to further modification

Repeated exposure to a mixture of two odors can increase their perceived similarity to each other when presented separately. Experiment 1 failed to detect any reduction of this effect by an interference treatment consisting of separate exposures to the odors after they had first been presented as a mixture. Exposure to a mixture also results in participants mistakenly rating this mixture and its elements as having occurred with equal frequency (i.e., confusing the mixture and its elements). The interference treatment did not affect this either, whereas it did change judgments about the frequency of a color–odor mixture and its elements. The greater resistance to interference of odor–odor learning compared to color–odor learning may result from configural encoding of odor–odor mixtures. Experiment 2 found that separate exposures to two odors not previously mixed decreased their perceived similarity. This result was inconsistent with the possibility that the interference treatment in Experiment 1 had tended to increase the similarity of the two odors, for example, by a process of sensory adaptation. Rather it suggested a process akin to acquired distinctiveness.     

Novel associative processing and aging: effect on creative production

ABSTRACT

Creative production has been reported to decline with age. This study investigated age-related differences in creative verbal production. Participants were 30 younger and 30 older adults. Study testing included language and cognitive assessments and the experimental task wherein participants created short stories incorporating words that are not commonly related, semantically or associatively. The resulting stories were rated by independent blinded judges for originality, cohesion, appropriateness, and organization. Younger adults' stories were rated as being significantly more original and more appropriate. Integrating unrelated words to create original stories requires activating widely distributed lexical-semantic networks to develop novel associations. Potential decreased neural network connectivity due to white matter degradation, commonly seen in normal aging, as well as decrements in front-executive disengagement may have affected older adults' performance on this story creation task. Future research using neuroimaging may elucidate possible neuroanatomic correlates of age-related changes in associative creative production..     

When your heart is in your mouth: the effect of second language use on negative emotions

Research on bilingualism and emotions has shown stronger emotional responses in the native language (L1) compared to a foreign language. We investigated the potential of purposeful second language (L2) use as a means of decreasing the experience of psychological distress. Native Swedish speakers read and answered questions about negative and neutral texts in their L1 (Swedish) and their L2 (English) and were asked to rate their level of distress before or after the questions. The texts and associated questions were either written in the same (within-language), or different languages (cross-language). We found that within-language trials when the text was written in participants’ native language (Swedish–Swedish) resulted in an increase of distress, whilst cross-language trials (Swedish–English) resulted in a decrease of distress. This implies that purposeful second language use can diminish levels of distress experienced following a negative event encoded in one's first language.     

The effect of aging in recollective experience: the processing speed and executive functioning hypothesis

This study was designed to investigate the effects of aging on consciousness in recognition memory, using the Remember/Know/Guess procedure (Gardiner, J. M., & Richarson-Klavehn, A. (2000). Remembering and Knowing. In E. Tulving & F. I. M. Craik (Eds.), The Oxford Handbook of Memory. Oxford University Press.). In recognition memory, older participants report fewer occasions on which recognition is accompanied by recollection of the original encoding context. Two main hypotheses were tested: the speed mediation hypothesis (Salthouse, T. A. (1996). The processing-speed theory of adult age differences in cognition. Psychological Review, 3, 403–428) and the executive-aging hypothesis (West, R. L. (1996). An application of prefrontal cortex function theory to cognitive aging. Psychological Bulletin, 120, 272–292). A group of young and a group of older adults took a recognition test in which they classified their responses according to Gardiner, J. M., & Richarson-Klavehn, A. (2000). Remembering and Knowing. In E. Tulving & F. I. M. Craik (Eds.), The Oxford Handbook of Memory. Oxford University Press. remember-know-guess paradigm. Subsequently, participants completed processing speed and executive function tests. The results showed that among the older participants, R responses decreased, but K responses did not. Moreover, a hierarchical regression analysis supported the view that the effect of age in recollection experience is determined by frontal lobe integrity and not by diminution of processing speed.     

路径知识习得的认知老化效应

年龄与路径知识习得的关系是空间与认知老化两大领域研究的重要议题。老年人在面对不同的路径学习环境时呈现出不同的认知老化表现。以往与年龄相关的路径知识习得能力变化的研究, 主要支持了认知老化衰退理论。然而近来发现随着年龄增长, 老年人保留了一种空间认知补偿能力。由此, 在对前人文献进行回顾和反思的基础上, 整合路径知识习得的认知老化表现及机制以探究缓解空间认知老化可能的内部因素和外部有效措施。     

日常前瞻记忆的年龄差异

在年龄—前瞻记忆悖论现象中,老年人在完成日常前瞻记忆任务时,其表现优于年轻人的现象尤其引人注意。研究者一方面探讨了动机水平、责任心、生活状态以及外部帮助与提示等与主体有关的因素等对这一结果的影响;另一方面也研究了任务本身因素的影响,根据不同任务情境和任务性质的前瞻记忆年龄比较的结果,可以推断日常前瞻记忆年龄差异的来源在于任务的性质而非任务的情境。将来的研究可通过元分析、中介效应检验等手段进一步确定日常前瞻记忆年龄差异的机制。     

The effect of aging on the memory enhancement of the survival judgment task

This study investigated whether or not aging affected the benefit of a survival judgment task. Sixteen young adults and 16 older adults participated in this experiment. In the survival task, participants were requested to judge whether a word was necessary or not in a survival situation. In the self‐referent judgment task, participants were requested to judge how easily the word brings to mind an important personal experience. Participants in each condition were presented 18 concrete nouns at 4‐s intervals. Our results showed that even though the survival judgment task enhanced the memory performance in both the young adults and the older adults, the young adults outperformed the older adults in the survival and self‐referent judgment tasks.     

Parallel effects of aging and time pressure on memory for source: evidence from the spacing effect

Two experiments address the degree to which item memory-the ability to remember that a word has been presented-is dissociable from source memory, or the ability to remember the context of that word's presentation. Spacing (as opposed to massing) an item's two presentations leads young adults to endorse that item more often when they are instructed to recognize it and to reject it more often when they are instructed to exclude it. Old adults also enjoy beneficial effects of spacing when the item is to be recognized, but suffer detrimental effects of the spacing manipulation when the item is to be rejected: They falsely endorse the spaced to-be-rejected items more than the massed ones. This dissociation also obtains with young subjects under conditions of increased time pressure: Under normal decision conditions, the ability to endorse to-be-recognized items and to reject to-be-rejected items increases with spacing; under speeded conditions, the ability to reject the latter items decreases with spacing. The results support the notion that source memory is selectively impaired in the elderly and that it is difficult to access mnemonic information about source under time pressure.     

Semantic categorical flexibility and aging: effect of semantic relations on maintenance and switching

The authors studied the effects of aging on the flexible use of categorization rules based on thematic and taxonomic relations. Two components of flexibility were distinguished: maintenance of a categorical relation, and switching between two relations. Results showed that age affects these two components. In older adults, an effect of the nature of the categorical relations to be used was revealed. Older adults demonstrated a specific difficulty in the flexible use of taxonomic relations. Moreover, all adults, independent of their age, showed better performance in maintaining the use of a categorical relation than in switching between two categorical relations.     

Cognitive operations in the generation effect on a recall test: role of aging and divided attention

Generation effect (generated words are better memorized than read words) of anagrams, rhymes, and associates of target words was examined in young, elderly, and very old subjects. Experiments 1 and 2 showed that only young subjects benefit from the generation effect in a free-recall test when the rule is of a phonological nature. Experiments 3, 4, and 5 showed that the generation effect of rhymes was due to a resources-dependent self-initiated process. Experiments 4 and 5 showed that in a divided-attention situation, generation effect of rhymes is not significant in young subjects, but that the generation effect of semantic associates remains significant for both groups (Experiment 5). The results are discussed within the environmental support framework and the transfer-appropriate processing framework.     

Regaining lost time: adult aging and the effect of time restoration on recall of time-compressed speech.

Two experiments in which time was restored to artificially accelerated (time-compressed) speech are reported. Experiment 1 showed that although both young and older adults' recall of the speech benefited from the restoration of time, time restoration failed to boost the older adults to their baseline levels for unaltered speech. In Experiment 2, either 100% or 125% of lost time was restored by inserting pauses, either at linguistic boundaries or at random points within the passages. Experiment 2 showed that the beneficial effects of time restoration depended on where processing time was inserted, as well as how much time was restored. Results are interpreted in terms of age-related slowing in speech processing moderated by preserved linguistic knowledge and short-term conceptual memory.     

Reserve capacity of the elderly in aging sensitive tests of fluid intelligence: a reanalysis via a structural equation modelling approach

In the last decade there has been a growing interest among developmental psychologists to investigate whether the cognitive performance of older adults can be improved by means of training programs. A number of cognitive training studies involving aging sensitive abilities of fluid intelligence have been performed with healthy older adults (Willis et al. 1981; Baltes et al., 1984/1986). In this paper we reanalyse data from Baltes et al. (1986) concerning the ADEPT Induction, ADEPT Figural Relations, Induction Standard and the Raven's Advanced Progressive Matrices Tests. In contrast to the above study, where the data analysis was based on a MANOVA approach, usually carried out when experimental data were gathered, this discussion implements an approach to change measurement for which the structural equation of different aspects of change in means as manifested in the moment matrices. The results here confirm these by Baltes et al. (1986), and suggest conclusions concerning change in means over time in the experimental and control groups, which are not implied by their study.     

The aging decision maker: cognitive aging and the adaptive selection of decision strategies

Are older adults' decision abilities fundamentally compromised by age-related cognitive decline? Or can they adaptively select decision strategies? One study (N = 163) investigated the impact of cognitive aging on the ability to select decision strategies as a function of environment structure. Participants made decisions in either an environment that favored the use of information-intensive strategies or one favoring the use of simple, information-frugal strategies. Older adults tended to (a) look up less information and take longer to process it and (b) use simpler, less cognitively demanding strategies. In accordance with the idea that age-related cognitive decline leads to reliance on simpler strategies, measures of fluid intelligence explained age-related differences in information search and strategy selection. Nevertheless, both young and older adults seem to be equally adapted decision makers in that they adjust their information search and strategy selection as a function of environment structure, suggesting that the aging decision maker is an adaptive one.     

Differential effect of aging on synaptic plasticity in the ventral and dorsal striatum

Both the ventral and dorsal striatum are involved in various forms of motor, motivational and learning behaviors. Previously, we demonstrated that several striatum-dependent motor and learning behaviors were reduced in mice with increased age. In this study, we investigated the effects of aging on synaptic plasticity in brain slices containing the nucleus accumbens (NAc) or caudate-putamen (CPu), using electrophysiological recordings. We showed that long-term depression (LTD) was reduced or absent in the NAc of aged C57BL/6 mice, whereas the amount of LTD in the CPu of young and aged mice was similar. The LTD induced by 10-Hz stimulation is NMDAR-dependent in the NAc, but NMDAR-independent in the CPu. Our results suggest that NAc LTD may be more sensitive than CPu LTD to the effects of normal aging with a possibility that NMDAR-dependent LTD may be more susceptible to the aging process than non-NMDAR LTD. We also showed that paired-pulse facilitation was diminished in the NAc and CPu in aged mice, suggesting that aging is accompanied by significant decline in presynaptic function in both the ventral and dorsal striata. The age-related reduction in synaptic plasticity may be a cellular mechanism underlying the age-related impairments in striatum-dependent motor and cognitive functions.