Food Cup Research Articles

Attract-and-Kill and Other Pheromone-Based Methods to Suppress Populations of the Indianmeal Moth (Lepidoptera: Pyralidae)

Three attract-and-kill formulations, a gel, a wax panel, and a plastic cylinder were tested in simulated warehouses at three densities of devices and at three densities of moths, Plodia interpunctella Hübner, per room. Wax panels and the cylinder formulations suppressed all the densities of moths with only one device per room. Two field experiments were then conducted during 2005 and 2006 in replicated commercial pet food and grocery stores that harbored natural populations of P. interpunctella. In the summer of 2005, the wax panel formulation suppressed adult male response to monitoring traps and also reduced the numbers of larvae in food bait oviposition cups after the first month of being established. This suppression was maintained until the third month. The second field experiment in 2006 compared three pheromone-based methods of moth suppression in buildings with moth populations in untreated buildings. The mass-trapping treatment showed the lowest adult moth capture after the first month of the experiment until the end of the third month. However, this treatment was similar statistically to use of attract-and-kill panels, mating disruption, and untreated control establishments in most of the weeks. Monitoring of larvae in food cups revealed the pheromone-based methods were not significantly different from each other, but that they suppressed moth populations in most of the weeks when compared with untreated control buildings. This research shows potential for successful pheromone-based suppression methods for Indianmeal moths in commercial applications.

Mating disruption of Lasioderma serricorne (Coleoptera: Anobiidae) in stored product habitats using the synthetic pheromone serricornin

AbstractCigarette beetles, Lasioderma serricorne (F.) (Coleoptera: Anobiidae), cause significant damage to the multibillion dollar food and tobacco industries worldwide each year. A non‐insecticidal alternative to manage L. serricorne is the application of mating disruption, in which high levels of synthetic sex pheromone are released to create an atmosphere that results in males failing to mate females, thereby causing population suppression or extinction. The reported work used synthetic serricornin, the predominant sex pheromone of L. serricorne, in mating disruption trials conducted in selected food‐ and feed‐processing facilities in South Carolina during 2010 and 2011. Mills subjected to mating disruption trials were monitored using oviposition cups filled with larval food and pheromone traps for males that contained monitoring lures. Immediately after deployment of mating disruption dispensers, trap captures declined significantly and indicated a reduction in population levels, that is, there was ‘trap shutdown’. A significant reduction was observed in numbers of adult beetles caught in the traps 8 weeks before and 8 weeks after treatment in both years. Beetle numbers from pheromone traps in untreated buildings remained at similar levels or increased after the time of mating disruption deployment in treated buildings. The numbers of adults that emerged from oviposition food cups were generally low and varied irregularly in treated and untreated buildings and were determined to be of little value for assessing treatment effects on reproduction. These initial field studies in the USA suggest that release of the synthetic sex pheromone of L. serricorne for mating disruption can significantly inhibit proper orientation behaviour of male L. serricorne to females and may lead to pest population decline from mating disruption.

White-throated sparrows adjust behaviour in response to manipulations of barometric pressure and temperature

Correlational evidence suggests that animals may use changes in barometric pressure to predict or respond to changes in weather. Birds adjust the timing of migratory flights and migratory restlessness in response to changing weather, and they make facultative movements in response to storms during winter and breeding. Using the pressure chamber of a hypobaric climatic wind tunnel we tested the responses of white-throated sparrows, Zonotrichia albicollis, to experimental changes in air pressure alone, or air pressure and temperature in combination. Sparrows in wintering (short-day) condition were exposed to gradual changes in pressure/temperature at dawn that simulated large but realistic high- and low-pressure weather systems. During a drop in pressure, birds approached their food cup more quickly and moved more often. There was no effect of increasing pressure and no additional effects of temperature change. Sparrows in spring migratory condition (photostimulated) were exposed to pressure/temperature changes in the evening. Decreases in temperature resulted in less migratory restlessness during the first hour of night, but there was no additional effect of pressure changes. These experimental results indicate that white-throated sparrows can facultatively adjust their behaviour in direct response to changing barometric pressure and temperature.

Blocking in autoshaped lever-pressing procedures with rats.

Rats will approach and contact a lever whose insertion into the chamber signals response-independent food delivery. This "autoshaping" or "sign-tracking" phenomenon has recently attracted considerable attention as a platform for studying individual differences in impulsivity, drug sensitization, and other traits associated with vulnerability to drug addiction. Here, we examined two basic stimulus selection phenomena-blocking and overshadowing-in the autoshaped lever pressing of rats. Blocking and overshadowing were decidedly asymmetrical. Previously reinforced lever-extension conditioned stimuli (CSs) completely blocked conditioning to auditory cues (Exps. 1 and 2), and previously nonreinforced lever-extension CSs overshadowed conditioning to auditory cues. By contrast, conditioning to lever-extension CSs was not blocked by either auditory (Exp. 3) or lever-insertion (Exp. 4) cues, and was not overshadowed by auditory cues. Conditioning to a lever-insertion cue was somewhat overshadowed by the presence of another lever, especially in terms of food cup behavior displayed after lever withdrawal. We discuss several frameworks in which the apparent immunity of autoshaped lever pressing to blocking might be understood. Given evidence that different brain systems are engaged when different kinds of cues are paired with food delivery, it is worth considering the possibility that interactions among them in learning and performance may follow different rules. In particular, it is intriguing to speculate that the roles of simple cue-reinforcer contiguity, as well as of individual and aggregate reinforcer prediction errors, may differ across stimulus classes.

The effects of amphetamine sensitization on conditioned inhibition during a Pavlovian–instrumental transfer task in rats

Psychostimulant sensitization heightens behavioral and motivational responses to reward-associated stimuli; however, its effects on stimuli associated with reward absence are less understood. We examined whether amphetamine sensitization alters performance during Pavlovian-instrumental transfer (PIT) to conditioned excitors and inhibitors. We further sought to characterize the effects of amphetamine sensitization on learning versus performance by exposing rats to amphetamine prior to Pavlovian training or between training and test. Adult male Long-Evans rats were given conditioned inhibition (A+/AX-) and Pavlovian (B+) training, followed by variable-interval instrumental conditioning. Rats were sensitized to D-amphetamine (2mg/kg daily injections for 7days) or served as non-exposed controls. Rats were given a PIT test, in which they were presented with stimulus B alone or in compound with the conditioned inhibitor (BX). During the PIT test, control rats significantly reduced instrumental responding on BX trials (to approximately 50% of responding to B). Amphetamine sensitization prior to Pavlovian conditioning increased lever pressing on BX trials and reduced lever pressing on B trials compared to controls. Amphetamine sensitization between training and test increased lever pressing on B and BX trials compared to controls. No effects of sensitization were observed on conditioned food cup approach. Amphetamine sensitization increases instrumental responding during PIT to a conditioned inhibitor by enhancing the excitation of conditioned stimuli and reducing the inhibition of conditioned inhibitors.

Vaccination with Lentiviral Vector Expressing thenfa1Gene Confers a Protective Immune Response to Mice Infected with Naegleria fowleri

Naegleria fowleri, a pathogenic free-living amoeba, causes fatal primary amoebic meningoencephalitis (PAM) in humans and animals. The nfa1 gene (360 bp), cloned from a cDNA library of N. fowleri, produces a 13.1-kDa recombinant protein which is located on pseudopodia, particularly the food cup structure. The nfa1 gene plays an important role in the pathogenesis of N. fowleri infection. To examine the effect of nfa1 DNA vaccination against N. fowleri infection, we constructed a lentiviral vector (pCDH) expressing the nfa1 gene. For the in vivo mouse study, BALB/c mice were intranasally vaccinated with viral particles of a viral vector expressing the nfa1 gene. To evaluate the effect of vaccination and immune responses of mice, we analyzed the IgG levels (IgG, IgG1, and IgG2a), cytokine induction (interleukin-4 [IL-4] and gamma interferon [IFN-γ]), and survival rates of mice that developed PAM. The levels of both IgG and IgG subclasses (IgG1 and IgG2a) in vaccinated mice were significantly increased. The cytokine analysis showed that vaccinated mice exhibited greater IL-4 and IFN-γ production than the other control groups, suggesting a Th1/Th2 mixed-type immune response. In vaccinated mice, high levels of Nfa1-specific IgG antibodies continued until 12 weeks postvaccination. The mice vaccinated with viral vector expressing the nfa1 gene also exhibited significantly higher survival rates (90%) after challenge with N. fowleri trophozoites. Finally, the nfa1 vaccination effectively induced protective immunity by humoral and cellular immune responses in N. fowleri-infected mice. These results suggest that DNA vaccination using a viral vector may be a potential tool against N. fowleri infection.

The immune response induced by DNA vaccine expressing nfa1 gene against Naegleria fowleri

The pathogenic free-living amoeba, Naegleria fowleri, causes fatal primary amoebic meningoencephalitis in experimental animals and in humans. The nfa1 gene that was cloned from N. fowleri is located on pseudopodia, especially amoebic food cups and plays an important role in the pathogenesis of N. fowleri. In this study, we constructed and characterized retroviral vector and lentiviral vector systems for nfa1 DNA vaccination in mice. We constructed the retroviral vector (pQCXIN) and the lentiviral vector (pCDH) cloned with the egfp-nfa1 gene. The expression of nfa1 gene in Chinese hamster ovary cell and human primary nasal epithelial cell transfected with the pQCXIN/egfp-nfa1 vector or pCDH/egfp-nfa1 vector was observed by fluorescent microscopy and Western blotting analysis. Our viral vector systems effectively delivered the nfa1 gene to the target cells and expressed the Nfa1 protein within the target cells. To evaluate immune responses of nfa1-vaccinated mice, BALB/c mice were intranasally vaccinated with viral particles of each retro- or lentiviral vector expressing nfa1 gene. DNA vaccination using viral vectors expressing nfa1 significantly stimulated the production of Nfa1-specific IgG subclass, as well as IgG levels. In particular, both levels of IgG2a (Th1) and IgG1 (Th2) were significantly increased in mice vaccinated with viral vectors. These results show the nfa1-vaccination induce efficiently Th1 type, as well as Th2 type immune responses. This is the first report to construct viral vector systems and to evaluate immune responses as DNA vaccination in N. fowleri infection. Furthermore, these results suggest that nfal vaccination may be an effective method for treatment of N. fowleri infection.

Pupation Site Selection in Four Drosophilid Species: Aggregation and Contact

This study of pupation site selection was undertaken to assess the frequency and orientation of pupae making physical contact in four sympatric species in the family Drosophilidae: Drosophila melanogaster, D. simulans, D. funebris, and Zaprionus tuberculatus. Pupation behavior was assayed in a vial containing a small food cup. Using nearest-neighbor analysis, we found that pupae were aggregated. Furthermore, the frequency of contact between pupae was far greater than could be explained by chance, in all four species. In the three species of Drosophila, about a third of the contacts were between intimately paired pupae whose long axes were parallel; we call this arrangement synapsis. In Z. tuberculatus, most pupal contacts were unoriented. When D. melanogaster larvae were reared with each of the other species, heterospecific pupal contact, including synapsis, occurred. Our discovery of pupal contact in several drosophilids expands the known repertory of social behavior in this family.

Spatial Orientation in Japanese Quails (Coturnix coturnix japonica)

Finding a given location can be based on a variety of strategies, for example on the estimation of spatial relations between landmarks, called spatial orientation. In galliform birds, spatial orientation has been demonstrated convincingly in very young domestic chicks. We wanted to know whether adult Japanese quails (Coturnix coturnix japonica) without food deprivation are also able to use spatial orientation. The quails had to learn the relation of a food location with four conspicuous landmarks which were placed in the corners of a square shaped arena. They were trained to find mealworms in three adjacent food cups in a circle of 20 such cups. The rewarded feeders were located during training between the same two landmarks each of which showed a distinct pattern. When the birds had learned the task, all landmarks were displaced clockwise by 90 degrees. When tested in the new situation, all birds redirected their choices with respect to the landmark shift. In subsequent tests, however, the previously correct position was also chosen. According to our results, quails are using conspicuous landmarks as a first choice for orientation. The orientation towards the previously rewarded location, however, indicates that the neuronal representation of space which is used by the birds also includes more fine grain, less conspicuous cues, which are probably also taken into account in uncertain situations. We also presume that the rare orientation towards never rewarded feeders may be due to a foraging strategy instead of being mistakes.

Anti-amoebic properties of a Malaysian marine sponge Aaptos sp. on Acanthamoeba castellanii

Crude methanol extracts of a marine sponge, Aaptos aaptos, collected from three different localities namely Kapas, Perhentian and Redang Islands, Terengganu, Malaysia, were tested in vitro on a pathogenic Acanthamoeba castellanii (IMR isolate) to examine their anti-amoebic potential. The examination of anti-Acanthamoebic activity of the extracts was conducted in 24 well plates for 72 h at 30 °C. All extracts possessed anti-amoebic activity with their IC(50) values ranging from 0.615 to 0.876 mg/mL. The effect of the methanol extracts on the surface morphology of A. castellanii was analysed under scanning electron microscopy. The ability of the extracts to disrupt the amoeba cell membrane was indicated by extensive cell's blebbing, changes in the surface morphology, reduced in cell size and with cystic appearance of extract-treated Acanthamoeba. Number of acanthapodia and food cup was also reduced in this Acanthamoeba. Morphological criteria of apoptosis in Acanthamoeba following treatment with the sponge's extracts was determined by acridine orange-propidium iodide staining and observed by fluorescence microscopy. By this technique, apoptotic and necrotic cells can be visualized and quantified. The genotoxic potential of the methanol extracts was performed by the alkaline comet assay. All methanol extracts used were significantly induced DNA damage compared to untreated Acanthamoeba by having high percentage of scores 1, 2, and 3 of the DNA damage. Results from cytotoxicity and genotoxicity studies carried out in the present study suggest that all methanol extracts of A. aaptos have anti-amoebic properties against A. castellanii.

The traveling salesrat: insights into the dynamics of efficient spatial navigation in the rodent

Rodent spatial navigation requires the dynamic evaluation of multiple sources of information, including visual cues, self-motion signals and reward signals. The nature of the evaluation, its dynamics and the relative weighting of the multiple information streams are largely unknown and have generated many hypotheses in the field of robotics. We use the framework of the traveling salesperson problem (TSP) to study how this evaluation may be achieved. The TSP is a classical artificial intelligence NP-hard problem that requires an agent to visit a fixed set of locations once, minimizing the total distance traveled. We show that after a few trials, rats converge on a short route between rewarded food cups. We propose that this route emerges from a series of local decisions that are derived from weighing information embedded in the context of the task. We study the relative weighting of spatial and reward information and establish that, in the conditions of this experiment, when the contingencies are not in conflict, rats choose the spatial or reward optimal solution. There was a trend toward a preference for space when the contingencies were in conflict. We also show that the spatial decision about which cup to go to next is biased by the orientation of the animal. Reward contingencies are also shown to significantly and dynamically modulate the decision-making process. This paradigm will allow for further neurophysiological studies aimed at understanding the synergistic role of brain areas involved in planning, reward processing and spatial navigation. These insights will in turn suggest new neural-like architectures for the control of mobile autonomous robots.

Manipulations of start and food locations affect navigation on a foraging task

Rats were able to search multiple food cups in a foraging task and successfully return to a fixed, but not a variable, start location. Reducing the number of food cups to be searched resulted in an improvement in performance in the variable start condition. Performance was better when only one or two food cups had to be visited but was still impaired if the food was not found in the first cup searched. Variable start locations impaired performance when only one food cup had to be searched, if that cup was moved over the table. These findings suggest that there is an interaction between memory processes and the navigational processes that allows an animal to return to its start location after a foraging trip. It appears that a fixed location for the food or the start point of a foraging trip is a necessary precondition for accurate performance.

WSAVA Nutritional Assessment Guidelines

WSAVA Nutritional Assessment Guidelines

Neuronal correlates of normal and drug‐potentiated Pavlovian–instrumental transfer (Commentary on Saddoris et al.)

As Saddoris et al. (2011) emphasized in their exciting new study, reward-directed actions are often initiated or facilitated by conditional stimuli that have been independently associated with the reward. The influence of conditional cues over action is also thought to play a major role in drug addiction. Yet, vital as this process may be to learned behavior, it is a difficult one to isolate experimentally, and little is known about its mechanism at the level of neuronal activity. Here, the authors make new headway on the issue by measuring neural firing correlates of Pavlovian–instrumental transfer (PIT) in rats. The basic effect of PIT can perhaps be traced back to Estes (Estes, 1943, 1948), and is revealed by a three-phase protocol: (i) train an animal to associate a Pavlovian positive conditioned stimulus (CS+) cue, such as a tone, with reward; (ii) separately train the animal to associate an instrumental action, such as a lever press, with the reward; and (iii) present the CS+ with the levers available. In this last test phase, the animal will press the lever much more when the CS+ is presented, despite never having ‘learned’ this cue-press sequence as a means of obtaining a reward. Thus, the PIT test is able to isolate the invigoration of actions by independently learned Pavlovian stimuli. Saddoris et al. (2011) trained rats following this protocol, and also included a non-predictive CS− cue and an unrewarded lever as controls. On the PIT test day, firing of projection neurons was recorded in the nucleus accumbens core and shell, which are key substrates for the effect (Wyvell & Berridge, 2000; Corbit et al., 2001; Hall et al., 2001; Lex & Hauber, 2008). Behaviorally, the CS+ increased lever pressing, as confirmation of PIT. Neurally, many interesting accumbens firing differences are reported between direction of responses, stimuli evoking them, and recording sites, further building a view of substantial heterogeneity and information multiplexing in accumbens firing. A main finding to highlight was that PIT performance levels correlated with the number of core neurons that fired more to the CS+ than to the CS− or pre-cue baseline and with the number of shell neurons that fired during lever pressing more robustly when the CS+ was present (i.e. PIT-modulated). This potentially indicates a distinct contribution for the core in assigning motivational value to reward-predictive cues to arouse behavior, and for the shell in integrating learned cue and action information to guide PIT performance. In a separate experiment, rats underwent a period of cocaine self-administration after the learning phases, which led them, in the PIT test, to press even more during the CS+ than control groups. The clear PIT enhancement coincided with a similarly clear increase in the number of shell (but not core) neurons firing more to rewarded versus unrewarded stimuli and actions, as well as in the number of PIT-modulated neurons in both shell and core. Food cup entry and related firing was unaffected, bolstering the conclusion that firing reflected PIT rather than general reward pursuit or psychomotor activation. Thus, it would seem that these data reveal elements of firing plasticity that could contribute to the influence of dopamine on PIT (Dickinson et al., 2000; Wyvell & Berridge, 2000; Lex & Hauber, 2008), and to the inflated capacity of independently learned cues to motivate reward seeking in addiction states (Wyvell & Berridge, 2001). One suspects, on the basis of the many brain sites implicated in PIT, that the accumbens is contributing particular component features. Determining what functional coding features emerge in these other sites would be key to fleshing out the effect at a circuit level (Homayoun & Moghaddam, 2009), but it is a challenge, as sites for PIT span mesocorticolimbic and sensorimotor circuitry (e.g. see Holland & Petrovich, 2005; Yin et al., 2008). This effort might be aided by multisite recordings or targeted online manipulations of key firing patterns to causally control PIT, as well as task designs to dissociate general from outcome-specific forms of PIT (Blundell et al., 2001; Corbit & Balleine, 2005). For now, however, this work represents an important and ‘motivating’ step forwards.

Interactions between amygdala central nucleus and the ventral tegmental area in the acquisition of conditioned cue-directed behavior in rats

Rats orient to and approach localizable visual cues paired with food delivery. Previous studies from this laboratory show that the acquisition and expression of these learned cue-directed responses depend on integrity of a system including the central nucleus of the amygdala (CeA), the substantia nigra pars compacta (SNc) and the dorsolateral striatum (DLS). Other investigators have suggested that cue-directed behaviors may also depend on interaction between CeA and the ventral striatum, perhaps via CeA projections to the ventral tegmental area (VTA). In Experiment 1, we examined the effects of unilateral lesions of CeA and/or VTA on rats' acquisition of conditioned responses to visual cues paired with food. Contrary to the results of previous studies that examined interactions of CeA with either SNc or DLS, rats with contralateral disconnection lesions of CeA and VTA were unimpaired in their acquisition of cue-directed responses. By contrast, rats with lesions of both structures in the same hemisphere failed to learn cue-directed responses, but were normal in their acquisition of conditioned responses directed to the food cup. In Experiment 2, we attempted to characterize the influence of VTA on CeA by examining FOS induction in CeA by a visual cue for food in rats with unilateral lesions of VTA. The results suggested an excitatory influence of VTA on CeA in the presence of food cues. Implications of these results for brain circuits involved in learned orienting and incentive motivation are discussed.

Effects of serum response factor (SRF) deletion on conditioned reinforcement

Serum response factor (SRF) is a ubiquitously expressed stimulus-dependent transcription factor that regulates gene expression by binding to serum response element in the promoter region of target genes. Recent studies in mice have shown that SRF is important for activity-dependent gene expression and synaptic plasticity in the adult brain but is dispensable for neuronal survival. Given these important functions of SRF in the CNS, it is expected to play a critical role in several aspects of learning and memory. Here we evaluated the role of SRF in conditioned reinforcement using two lines of conditional SRF mutant mice. These SRF mutant mice exhibited different spatial patterns of SRF deletion in the post-natal forebrain and notably within the hippocampus. SRF deletion was more widespread in SRF-CKCre mutants than in SRF-SynCre mutants, particularly in areas of the cortex and striatum. Mutant and wild-type mice were trained to associate one auditory cue (CS+) with reward, whereas a second cue remained relatively neutral (CS−). All mice readily acquired this discrimination, entering the food cup during CS+ but not during CS−. In a subsequent test of conditioned reinforcement, in the absence of food, wild-type control mice and SRF-SynCre mice learned to selectively perform an instrumental response that yielded CS+ presentation rather than another response that produced CS−. SRF-CKCre mutants failed to show this preferential responding for CS+. These results suggest a role for SRF in conditioned reinforcement, a manifestation of incentive learning that has been implicated in many aspects of adaptive and maladaptive behavior, such as substance abuse and eating disorders.

Effects of physical exercise on ADHD‐like behavior in male and female adolescent spontaneously hypertensive rats

The present study examined the effects of exercising (voluntary wheel running) during adolescence on attentional function in male and female spontaneously hypertensive rats (SHRs), a commonly used animal model of attention-deficit/hyperactivity disorder (ADHD). Once rats reached adulthood, they received one session in which a light was presented 12 times but not reinforced, followed by training sessions in which the light was paired with a food reward. Male and female SHRs that had access to running wheels exhibited levels of unconditioned orienting behavior that were similar to Wistar-Kyoto rats (normo-active control) while SHRs that did not have access to running wheels exhibited higher levels of unconditioned orienting behavior. When the light was later paired with food there were no differences between the groups of male rats, but exercising female SHRs exhibited a decrease in conditioned food cup behavior. Consistent with their established phenotype, SHR rats exhibited more locomotor activity during an open field exploration session than WKY rats, but there was no relationship between orienting behavior and locomotor activity. Together these data suggest that physical exercise during adolescence can benefit attentional capabilities.

Involvement of retrosplenial cortex in forming associations between multiple sensory stimuli.

The retrosplenial cortex (RSP) is highly interconnected with medial temporal lobe structures, yet relatively little is known about its specific contributions to learning and memory. One possibility is that RSP is involved in forming associations between multiple sensory stimuli. Indeed, damage to RSP disrupts learning about spatial or contextual cues and also impairs learning about co-occurring conditioned stimuli (CSs). Two experiments were conducted to test this notion more rigorously. In Experiment 1, rats were trained in a serial feature negative discrimination task consisting of reinforced presentations of a tone alone and nonreinforced serial presentations of a light followed by the tone. Thus, in contrast to prior studies, this paradigm involved serial presentation of conditioned stimuli (CS), rather than simultaneous presentation. Rats with damage to RSP failed to acquire the discrimination, indicating that RSP is required for forming associations between sensory stimuli regardless of whether they occur serially or simultaneously. In Experiment 2, a sensory preconditioning task was used to determine if RSP was necessary for forming associations between stimuli even in the absence of reinforcement. During the first phase of this procedure, one auditory stimulus was paired with a light while a second auditory stimulus was presented alone. In the next phase of training, the same light was paired with food. During the final phase of the procedure both auditory stimuli were presented alone during a single session. Control, but not RSP-lesioned rats, exhibited more food cup behavior following presentation of the auditory cue that was previously paired with light compared with the unpaired auditory stimulus, indicating that a stimulus-stimulus association was formed during the first phase of training. These results support the idea that RSP has a fundamental role in forming associations between environmental stimuli.

Social intelligence in tufted capuchin monkeys

Tufted capuchin monkeys (Cebus apella), a species of New World primates, are known to be adept at various complex tool use both in the laboratory and in the wild. With their manual dexterity, they work as a helper for quadriplegic people. Social intelligence hypothesis, which places social intelligence as a major factor to advance complex information processing capability, predicts advanced social intelligence in this species with highly developed physical intelligence. In this paper, I describe a series of studies on social intelligence of this species in our comparative cognition laboratory at Kyoto University. As a competitive aspect of social intelligence, we analyzed spontaneous deceptive behavior between the monkeys. Two monkeys, dominant and subordinate, faced each other in the transparent boxes and two food cups were placed between them. When the subordinate monkey opened the baited cup, the dominant opponent was able to usurp the food. Some of the subordinates started to open the empty cup first: a behavior that could be interpreted as a deceptive act. As a cooperative aspect, we showed that two monkeys cooperated by dividing a sequence of behavior necessary to obtain rewards. This behavior continued even when only one of the participants received a reward if their roles were switched every trial; a reciprocal altruism was shown. To examine whether such complicated social behaviors reflect processes of mentalizing, we asked whether capuchin monkeys have cognitive components underlying them. We found that the monkeys are capable of recognizing attentional states of humans, inferring consequences of other's behavior, recognizing other's knowledge status, inferring the cause of other's emotional expression, and recognizing other's welfare. Thus these primitive aspects of mentalizing are clearly shared in species that is much more distant from humans than apes.

Single unit activity in the rat superior colliculus during reward magnitude task performance.

Long-Evans hooded rats were trained to run an alternation pattern in a t-maze with low reward (1 pellet) in the food cup of one arm and high reward (3 pellets) in the food cup of the other arm. Single units in the intermediate and deep layers of the superior colliculus were recorded using moveable microelectrodes. Most units showed activity that was associated with food retrieval, with a phasic increase in activity either upon the cessation of running or upon the insertion of the snout into the food cup. Some units (16%) showed different activity patterns upon retrieval of the two magnitudes of reward. Although 70% of the units showed either unimodal or multimodal sensory sensitivity, usually in response to tactile stimulation of the snout, this property was not related to activity associated with food retrieval. These data support previous observations that cells in the rat SC exhibit activity related to food retrieval, and indicate that for some of these neurons the coding reflects the characteristics of the reward stimulus.