Scientists have used brain imaging to probe how our canine companions process words they have been taught to associate with objects. Photo / 123RF
Scientists have used brain imaging to probe how our canine companions process words they have been taught to associate with objects. Photo / 123RF
When some dogs hear the word "ball", they look up and get excited.
But what does the word really mean to them?
Do canines take this as a signal that something's about to happen, or do they actually picture a tennis ball?
US researchers have tried to answer that question in one of the first studies using brain imaging to probe how our canine companions process words they have been taught to associate with objects.
Their findings suggest dogs have at least a rudimentary neural representation of meaning for words they have been taught, differentiating words they have heard before from those they have not.
"Many dog owners think that their dogs know what some words mean, but there really isn't much scientific evidence to support that," explained Ashley Prichard, of Atlanta's Emory University.
"We wanted to get data from the dogs themselves - not just owner reports."
While it was known that dogs have the capacity to process at least some aspects of human language as they could learn to follow their owners' verbal commands, previous research has suggested they may also rely on many other cues, such as a gaze, a gesture, or even an emotional expession.
The researchers focused on questions surrounding the brain mechanisms dogs use to differentiate between words, or even what constitutes a word to a dog.
Twelve dogs of varying breeds were trained for months by their owners to retrieve two different objects, based on the objects' names.
Each dog's pair of objects consisted of one with a soft texture, such as a stuffed animal, and another of a different texture, such as rubber, to facilitate discrimination.
Training consisted of instructing the dogs to fetch one of the objects and then rewarding them with food or praise.
Training was considered complete when a dog showed that it could discriminate between the two objects by consistently fetching the one requested by the owner when presented with both of the objects.
During one experiment, the trained dog lay in the fMRI scanner while the dog's owner stood directly in front of the dog at the opening of the machine and said the names of the dog's toys at set intervals, then showed the dog the corresponding toys.
Eddie, a golden retriever-Labrador mix, for instance, heard his owner say the words "Piggy" or "Monkey," then his owner held up the matching toy.
As a control, the owner then spoke gibberish words, such as "bobbu" and "bodmick," then held up novel objects like a hat or a doll.
The results showed greater activation in auditory regions of the brain to the novel pseudowords relative to the trained words.
The researchers hypothesise that the dogs may show greater neural activation to a novel word because they sense their owners want them to understand what they are saying, and they are trying to do so.
While dogs had varying capacity and motivation for learning and understanding human words, they nonetheless appeared to have a neural representation for the meaning of words they'd been taught.
But that didn't mean spoken words were the most effective way for an owner to communicate with their dog - in fact, the neural reward system of dogs was still more attuned to visual and to scent cues than to verbal ones.
"When people want to teach their dog a trick, they often use a verbal command because that's what we humans prefer," Prichard said.
"From the dog's perspective, however, a visual command might be more effective, helping the dog learn the trick faster."
The science of... sports rivalry
What makes rival sports fans see the same match differently? Photo / 123RF
In other quirky brain science, researchers have scanned the grey matter of die-hard soccer fans to find out why supporters of rival teams often have very different views on the same match.
When England played Colombia in the 2018 World Cup, many England fans complained about a high number of fouls from the Colombian side.
Simultaneously, in South America, a petition demanding a rematch because of the referee's unfair bias against the Colombian team rapidly gained hundreds of thousands of signatures.
The two vastly different perceptions of the same match left many people wondering; did Colombia and England supporters see the same game?
Now, researchers from the University of York have used MRI scanning to try and find out how people can have such different takes on football.
As part of the research they mapped and compared the brain activity of Manchester United and Chelsea supporters while they watched their beloved sides in action against one another.
The findings suggest that fans of rival teams do see the same match in a visual sense.
That is, the regions of the brain that are directly involved in seeing showed similar activity in both sets of supporters.
However, the results of the study showed clear differences between the groups in the activity of higher regions of the brain involved in cognition, indicating that the same sensory information was interpreted and evaluated differently.
"When we compared the brain activity of supporters of the same team and supporters of opposing teams, we found that activity in the sensory regions of the brain were aligned in all participants," York's Professor Tim Andrews explained.
"Or in other words, they all saw and heard the same game.
"But, in the frontal and subcortical regions of the brain - including areas known to be active in reward, self-identity and control of movement - there was a correlation between supporters of the same team, but significant differences between the groups.
"This is what allows fans of rival teams to develop a different understanding of the same game."
For the study, the researchers recruited keen supporters of Chelsea and Manchester United.
The participants had supported their team for an average of 15 years and had been to see them play over 25 times.
In an MRI scanner, participants were shown a Match-of-the-Day-style montage of highlights from games between the two teams.
One of the regions of the brain that showed the greatest differences between groups was the nucleus accumbens - an area central to the brain's reward system.
The research team suggest this link between group bias and reward may explain the ease and rapidity with which humans form groups and favour in-group members.
The research showed that multiple parts of the brain are involved in producing this group bias effect and that it reflects an interaction between a network of regions rather than a single mechanism.
"The results of our study offer new insight into the neural basis for group bias and the human tendency to feel comfort and reassurance when part of a group, alongside distrust of outsiders and rivals," Andrews added.
"The regions of the brain that showed the biggest differences between the groups of supporters - the subcortical regions positioned in the middle of the brain - are believed to have been conserved during evolution.
"This supports the idea that group mentality may reflect one of the more primitive human instincts."
