The degeneracy of behavior and the rise of neuroimaging to measure affective states in dogs

It is gratifying and significant that so many scientists from diverse fields are arguing in-depth regarding a particularly complex set of social emotions in a non-human animal. Emotions play a fundamental role in decision making and information processing. Neuroimaging is important in understanding the cognitive and emotional worlds of non-human animals and can help measure covert emotions lacking clear behavioral correlates. Various experimental approaches could clarify the relative importance of attachment and aggression in jealousy and whether the phenomenon we measured is more akin to human envy or jealousy. Reverse inference from amygdala activation is probably justified because behavior is “degenerate”: there are fewer behavioral programs than brain states that give rise to them. Individual differences are also important

The degeneracy of behavior and the rise of neuroimaging to measure affective states in dogs

It is gratifying and significant that so many scientists from diverse fields are arguing in-depth regarding a particularly complex set of social emotions in a non-human animal. Emotions play a fundamental role in decision making and information processing. Neuroimaging is important in understanding the cognitive and emotional worlds of non-human animals and can help measure covert emotions lacking clear behavioral correlates. Various experimental approaches could clarify the relative importance of attachment and aggression in jealousy and whether the phenomenon we measured is more akin to human envy or jealousy. Reverse inference from amygdala activation is probably justified because behavior is “degenerate”: there are fewer behavioral programs than brain states that give rise to them. Individual differences are also important

Intertemporal Choice - Toward an Integrative Framework

Intertemporal choices are decisions with consequences that play out over time. These choices range from the prosaic–-how much food to eat at a meal– to life--changing decisions about education, marriage, fertility, health behaviors and savings. Intertemporal preferences also affect policy debates about long-run challenges, such as global warming. Historically, it was assumed that delayed rewards were discounted at a constant rate over time. Recent theoretical and empirical advances from economic, psychological and neuroscience perspectives, however, have revealed a more complex account of how individuals make intertemporal decisions. We review and integrate these advances. We emphasize three different, occasionally competing, mechanisms that are implemented in the brain: representation, anticipation and self-control.Economic

Scent of the familiar: An fMRI study of canine brain responses to familiar and unfamiliar human and dog odors

Understanding dogs’ perceptual experience of both conspecifics and humans is important to understand how dogs evolved and the nature of their relationships with humans and other dogs. Olfaction is believed to be dogs’ most powerful and perhaps important sense and an obvious place to begin for the study of social cognition of conspecifics and humans. We used fMRI in a cohort of dogs (N = 12) that had been trained to remain motionless while unsedated and unrestrained in the MRI. By presenting scents from humans and conspecifics, we aimed to identify the dimensions of dogs’ responses to salient biological odors – whether they are based on species (dog or human), familiarity, or a specific combination of factors. We focused our analysis on the dog\u27s caudate nucleus because of its well-known association with positive expectations and because of its clearly defined anatomical location. We hypothesized that if dogs’ primary association to reward, whether it is based on food or social bonds, is to humans, then the human scents would activate the caudate more than the conspecific scents. Conversely, if the smell of conspecifics activated the caudate more than the smell of humans, dogs’ association to reward would be stronger to their fellow canines. Five scents were presented (self, familiar human, strange human, familiar dog, strange dog). While the olfactory bulb/peduncle was activated to a similar degree by all the scents, the caudate was activated maximally to the familiar human. Importantly, the scent of the familiar human was not the handler, meaning that the caudate response differentiated the scent in the absence of the person being present. The caudate activation suggested that not only did the dogs discriminate that scent from the others, they had a positive association with it. This speaks to the power of the dog\u27s sense of smell, and it provides important clues about the importance of humans in dogs’ lives

Jealousy in dogs? Evidence from brain imaging

Domestic dogs are highly social and have been shown to be sensitive not only to the actions of humans and other dogs but to the interactions between them. We used the C-BARQ scale to estimate dogs’ aggressiveness, and we used noninvasive brain imaging (fMRI) to measure activity in their amygdala (an area involved in aggression). More aggressive dogs had more amygdala activation data while watching their caregiver give food to a realistic fake dog than when they put the food in a bucket. This may have some similarity to human jealousy, adding to a growing body of evidence that differences in specific brain activities correlate with differences in canine temperament. The amygdala response habituates when an interaction is observed repeatedly, suggesting that repeated exposures may be a useful behavioral intervention with potentially aggressive dogs

Temporal Prediction Errors in a Passive Learning Task Activate Human Striatum

AbstractFunctional MRI experiments in human subjects strongly suggest that the striatum participates in processing information about the predictability of rewarding stimuli. However, stimuli can be unpredictable in character (what stimulus arrives next), unpredictable in time (when the stimulus arrives), and unpredictable in amount (how much arrives). These variables have not been dissociated in previous imaging work in humans, thus conflating possible interpretations of the kinds of expectation errors driving the measured brain responses. Using a passive conditioning task and fMRI in human subjects, we show that positive and negative prediction errors in reward delivery time correlate with BOLD changes in human striatum, with the strongest activation lateralized to the left putamen. For the negative prediction error, the brain response was elicited by expectations only and not by stimuli presented directly; that is, we measured the brain response to nothing delivered (juice expected but not delivered) contrasted with nothing delivered (nothing expected)

Striatal topography of probability and magnitude information for decisions under uncertainty

Most decisions involve some element of uncertainty. When the outcomes of these decisions have different likelihoods of occurrence, the decision-maker must consider both the magnitude of each outcome and the probability of its occurrence, but how do individual decision makers combine the two dimensions of magnitude and probability? Here, we approach the problem by separating in time the presentation of magnitude and probability information, and focus the analysis of fMRI activations on the first piece of information only. Thus, we are able to identify distinct neural circuits for the two dimensions without the confounding effect of divided attention or the cognitive operation of combining them. We find that magnitude information correlates with the size of the response of the ventral striatum while probability information correlates with the response in the dorsal striatum. The relative responsiveness of these two striatal regions correlates with the behavioral tendency to weight one more than the other. The results are consistent with a second-order process of information aggregation in which individuals make separate judgments for magnitude and probability and then integrate those judgments

Diffusion Tensor Imaging of Dolphin Brains Reveals Direct Auditory Pathway to Temporal Lobe

The brains of odontocetes (toothed whales) look grossly different from their terrestrial relatives. Because of their adaptation to the aquatic environment and their reliance on echolocation, the odontocetes’ auditory system is both unique and crucial to their survival. Yet, scant data exist about the functional organization of the cetacean auditory system. A predominant hypothesis is that the primary auditory cortex lies in the suprasylvian gyrus along the vertex of the hemispheres, with this position induced by expansion of ‘associative0 regions in lateral and caudal directions. However, the precise location of the auditory cortex and its connections are still unknown. Here, we used a novel diffusion tensor imaging (DTI) sequence in archival post-mortem brains of a common dolphin (Delphinus delphis) and a pantropical dolphin (Stenella attenuata) to map their sensory and motor systems. Using thalamic parcellation based on traditionally defined regions for the primary visual (V1) and auditory cortex (A1), we found distinct regions of the thalamus connected to V1 and A1. But in addition to suprasylvian-A1, we report here, for the first time, the auditory cortex also exists in the temporal lobe, in a region near cetacean-A2 and possibly analogous to the primary auditory cortex in related terrestrial mammals (Artiodactyla). Using probabilistic tract tracing, we found a direct pathway from the inferior colliculus to the medial geniculate nucleus to the temporal lobe near the sylvian fissure. Our results demonstrate the feasibility of postmortem DTI in archival specimens to answer basic questions in comparative neurobiology in a way that has not previously been possible and shows a link between the cetacean auditory system and those of terrestrial mammals. Given that fresh cetacean specimens are relatively rare, the ability to measure connectivity in archival specimens opens up a plethora of possibilities for investigating neuroanatomy in cetaceans and other species