what is the grandmother cell hypothesis

Full Answer

What is the Grandma hypothesis?

The grandmother hypothesis is a hypothesis to explain the existence of menopause in human life history by identifying the adaptive value of extended kin networking.

What is the Grandma cell?

The grandmother cell is a hypothetical neuron that represents a complex but specific concept or object. It activates when a person "sees, hears, or otherwise sensibly discriminates" a specific entity, such as his or her grandmother.

What is the opposite of the grandmother cell theory?

The grandmother cell hypothesis, is an extreme version of the idea of sparseness, and is not without critics. The opposite of the grandmother cell theory is the distributed representation theory, that states that a specific stimulus is coded by its unique pattern of activity over a large group of neurons widely distributed in the brain.

Is there a ‘grandmother cell’ for object recognition?

This ‘ grandmother cell ’ hypothesis has been critiqued elsewhere, but it is worth noting that plausible models of object recognition suggest the need for grandmother cell-like coding for certain tasks (e.g., distinguishing between different faces) and sparse population codes for other tasks (e.g., categorization).

What is a grandmother cell psychology?

512): “The term “grandmother cell” refers to a neuron that would respond only to a specific, complex, and meaningful stimulus, that is, to a single percept or even a single concept. As originally conceived, a grandmother cell was multimodal, but the term came to be used mostly for representing a visual percept.”

Why is the grandmother cell theory thought not to be correct?

There are many neurons in the brain, but not enough for each object and name that you know. An even deeper reason to be skeptical of the grandmother cell hypothesis is that the function of a sensory neuron is only partially determined by its response to sensory inputs.

Why are grandmother neurons controversial?

In the 1960s, some neuroscientists thought a single brain cell called the "grandmother neuron" would light up only at the sight of your grandmother's face. Almost immediately, neuroscientists began to dismiss the theory — a single neuron could not correspond to one idea or person, they argued.

Do grandmother neurons exist?

Scientists have since discovered plenty of sensory neurons that specialize in processing facial information, and as many memory cells dedicated to storing data from personal encounters. But a grandmother neuron, or even a hybrid cell capable of linking vision to memory, never emerged.

Is there any evidence for grandmother cells?

The idea of grandmother cells describes a hypothetical neuron which encodes and responds to a highly specific but complex stimulus, such as one's grandmother (Barlow, 2009). Current neuroscience has not disproved but mainly forgotten about this idea, yet it occasionally resurfaces in popular science.

Are grandmother cells selective?

These cells are selective in that they do not fire for other visual objects important for monkeys such as fruit and genitalia.

What are Gnostic cells?

The grandmother cell, also known as the gnostic neuron, is a hypothetical neuron that represents a person's grandmother or, more generally, any complex and specific concept or object. A grandmother cell activates when a person "sees, hears, or otherwise sensibly discriminates" his or her grandmother.

How is a specific person's face represented by the nervous system?

A specific person's face is represented in the nervous system by the firing of: a group of neurons each responding to a number of different faces.

What is LTP in neuroscience?

Long-term potentiation (LTP) is a process involving persistent strengthening of synapses that leads to a long-lasting increase in signal transmission between neurons. It is an important process in the context of synaptic plasticity. LTP recording is widely recognized as a cellular model for the study of memory.

How does your brain recognize faces?

The ability to recognize faces is so important in humans that the brain appears to have an area solely devoted to the task: the fusiform gyrus. Brain imaging studies consistently find that this region of the temporal lobe becomes active when people look at faces.

What are face cells?

'Face cells' are visual neurons that selectively respond more to faces than other objects. Clustered together in inferotemporal cortex, they are thought to form a network of modules specialized in face processing by encoding face-specific features.

What is the population code?

In this article, we focus on one type of neural code, known as population codes, which are used to encode many features throughout the nervous system. A population code is a way of representing informa- tion about a feature through the simultaneous activity of a large set of neurons sensitive to the feature.

What contradicts the cell theory?

The cell theory states that all living things are made of cells, cells are the basic units of structure and function of living things, and that all cells come from other cells. Since viruses are not made of cells, and do not use cells in any of their processes, they are not related to the cell theory.

What are the implications of the cell theory for the theory of evolution?

Implications of the Cell Theory. All cells come from preexisting cells, all individuals in a population of single-celled organisms are related by common ancestry. All of the cells present in a multicellular organism have descended from preexisting cells and are connected by common ancestry.

What is the second cell theory?

The second part of cell theory was that new cells are formed from preexisting cells. The third part is that all cells are similar. Finally, cells are the most basic units of life. In other words, everything is made up of cells.

Who established cell theory and highlight the statement of cell theory?

The classical cell theory was proposed by Theodor Schwann in 1839. There are three parts to this theory. The first part states that all organisms are made of cells. The second part states that cells are the basic units of life.

What is the grandmother hypothesis?

The grandmother hypothesis is a hypothesis to explain the existence of menopause in human life history by identifying the adaptive value of extended kin networking. It builds on the previously postulated " mother hypothesis " which states that as mothers age, the costs of reproducing become greater, ...

Why is the grandmother hypothesis controversial?

Some critics have cast doubt on the hypothesis because while it addresses how grandparental care could have maintained longer female post-reproductive lifespans, it does not provide an explanation for how it would have evolved in the first place. Some versions of the grandmother hypothesis asserted that it helped explain the longevity of human senescence. However, demographic data has shown that historically rising numbers in older people among the population correlated with lower numbers of younger people. This suggests that at some point grandmothers were not helpful toward the survival of their grandchildren, and does not explain why the first grandmother would forgo her own reproduction to help her offspring and grandchildren.

Why are grandmothers important?

Because of this correlation, human grandmothers are well-poised to provide supplemental parental care to their offspring's children. Since their grandchildren still carry a portion of their genes, it is still in the grandmother’s genetic interest to ensure those children survive to reproduction.

How does the grandmother hypothesis explain menopause?

The grandmother hypothesis is a hypothesis to explain the existence of menopause in human life history by identifying the adaptive value of extended kin networking. It builds on the previously postulated " mother hypothesis " which states that as mothers age, the costs of reproducing become greater, and energy devoted to those activities would be better spent helping her offspring in their reproductive efforts. It suggests that by redirecting their energy onto those of their offspring, grandmothers can better ensure the survival of their genes through younger generations. By providing sustenance and support to their kin, grandmothers not only ensure that their genetic interests are met, but they also enhance their social networks which could translate into better immediate resource acquisition. This effect could extend past kin into larger community networks and benefit wider group fitness.

Why is menopause an adaptation?

Williams suggested that at some point it became more advantageous for women to redirect reproductive efforts into increased support of existing offspring. Since a female's dependent offspring would die as soon as she did, he argued, older mothers should stop producing new offspring and focus on those existing. In so doing, they would avoid the age-related risks associated with reproduction and thereby eliminate a potential threat to the continued survival of current offspring. The evolutionary reasoning behind this is driven by related theories.

Does the grandmother effect explain longevity?

In addition, all variations on the mother, or grandmother effect, fail to explain longevity with continued spermatogenesis in males. Another problem concerning the grandmother hypothesis is that it requires a history of female philopatry.

Do chimpanzees have oocyte atresia?

In chimpanzees, our closest nonhuman, genetic relatives, there is a very similar rate of oocyte atresia until the age of 35 at which point humans experience a far accelerated rate compared to chimpanzees. However, chimpanzee females, unlike humans, usually die while still in their reproductive phase.

Selectionism and the Brain

In this view, there are no innate mechanisms for complex personal recognition, such as the “grandmother cell” postulated by researchers in the 1970s to correspond to one's perception of one's grandmother.7 Nor is there any “master area,” or “final common path,” whereby all perceptions relating (say) to one's grandmother converge in one single place.

Computational Neuroscience

E.T. Rolls, in Reference Module in Neuroscience and Biobehavioral Psychology, 2017

Population Coding

Population coding in its narrowest sense involves a large population of broadly tuned neurons, whereas single-neuron coding in its narrowest sense involves one highly specialized neuron for each function.

Vision II

T. Fukushima, ... Y. Miyashita, in The Senses: A Comprehensive Reference, 2008

Handbook of in Vivo Neural Plasticity Techniques

Lukas Kunz, ... Nikolai Axmacher, in Handbook of Behavioral Neuroscience, 2018

Perception: The Binding Problem and the Coherence of Perception

The simplest way to bind features together is to have all the detectors of the simple features converge on a single ‘cardinal cell.’ This cell would then serve as a detector of the compound object.

Selectionism and the Brain

There is an important connection between memory and categorization. The way animals or humans categorize stimuli in their environments has a deep impact on the way memory is stored and accessed in their nervous systems.

What is grandmother cell theory?

But the important point for present purposes is that a grandmother cell theory is a theory about how we recognize *familiar* categories – people like your grandmother, not unfamiliar people. No theory (grandmother or otherwise) predicts that single cells in monkey brains should selectively respond to unfamiliar human faces.

What was the key finding that the authors took to refute grandmother cells?

What was the key finding that the authors took to refute grandmother cells? They failed to find any cells in monkey IT cortex that selectively responded to unfamiliar human faces. Instead, they found neurons that responded to single dimensions within a 50-dimensional “face space”, with a pattern of activation over ~ 200 of these neurons coding for these faces. That is, these faces were coded by distributed rather than grandmother cells.

Why did Plaut and McCelland reject grandmother cells?

Just as Chang and Tsao (2017), Plaut and McCelland rejected grandmother cells because there just not enough neurons to code for all experiences. They note it is not possible to have a neuron devoted to a specific tulip on McClelland’s dining room table. Again, I gave the same response:

Do neurons represent familiar categories?

But there is an interesting alternative grandmother cell hypothesis that a few researchers do entertain, namely, the view that some neurons selectively represent familiar categories, things like familiar faces, words, and objects. On this view, single neurons respond most strongly to inputs from one specific category, although the neuron may respond to a lesser degree to inputs from similar categories. The category is identified when the neuron fires beyond some threshold. This requires considerably less than 6 billion grandmother cells devoted to faces. Nevertheless, critics of grandmother cells keep rejecting the straw-man version, and don’t seem to even appreciate that there is an alternative hypothesis that they should consider.

Do Chang and Tsao argue against grandmother cells?

But the more important point is that the Chang and Tsao paper provide no evidence against grandmother cells. The problem is that the authors have a basic misunderstanding of the hypothesis, and as a result, they have not carried out a relevant experiment.

Why are grandmothers important?

In her piece in the New Republic that analyzes the “grandmother hypothesis” Judith Shulevitz writes of another very positive reason for grandmothers — As the grandmother effect spread throughout the population over thousands of generations, it changed humans in another way. It made their brains bigger. As life lengthened, so did each stage of it. Children stayed children longer, which let their brains develop a more complex neural architecture.

Why do women help their grandchildren?

From these observations, came the “grandmother hypothesis.” Simply stated: women past childbearing age help not just their children, but their children’s children. They strengthen the genealogy of the family, insuring that the line will continue. Having such a role or purpose eventually lengthened their own life span. When no longer required to carry an infant around, they were freed up to do work that helped their progeny. And very importantly, by foraging for more food, they prevented their grandchildren from dying. All generations were aided as the lengthening of the life span was then passed on.

Why is it important for grandparents to be protective?

Kate Fogarty, PhD, stressed the importance of the protective role grandparents can play when grandchildren are cared for by a depressed mother. Her research showed that the formation of loving bonds between grandparents and those children could help develop positive behavior, increase cognitive development and prevent behavioral problems. She even went so far as to say that the possibility of the depression being passed to these children could be broken by the grandparent/grandchild relationship–a win win.

What can grandparents do?

Grandparents can be a source of information, providing advice, guidance and just plain helping out–like locating the phone number of a doctor.

What is the saying "If I'd known how wonderful it is to have grandchildren, I would have had them first?

There’s the familiar line: “If I’d known how wonderful it is to have grandchildren, I would have had them first.” What is that all about? Probably that with grandchildren comes experience, confidence in the role to be played, freedom from the harder aspects of child-rearing and the amazing chance to see once again the future in a child’s eyes.

Do grandparents like to read books?

But hopefully most grandparents find the middle acceptable ground –they are eager to role up their sleeves and help when needed and they are always desirous of telling family stories, reading well-loved books, taking exploratory walks or singing well-loved songs. It’s a little like reliving your parenting. It’s a lot like looking into the future and once again having that uplifting feeling of knowing something of you will live on. That’s truly important.

Can grandparents babysit?

Grandparents can babysit, allowing stressed moms and dads a chance to get away and relate to one another.

Why did the researchers come up with the Grandmother Hypothesis?

The hypothesis is that the help of grandmothers enables mothers to have more children. So women who had the genetic makeup for longer living would ultimately have more grandchildren carrying their longevity genes.

Who discovered the grandmother hypothesis?

The first hard evidence for the grandmother hypothesis was gathered by Kristen Hawkes, an anthropologist at the University of Utah who was studying the Hadza people, a group of hunter-gatherers in northern Tanzania. Hawkes was struck by "how productive these old ladies were" at foraging for food, and she later documented how their help allowed mothers to have more children.

How many children did women have when they lived 200 miles from their mom?

It turned out that staying close to grandma paid off in family size. Women who lived 200 miles from mom had, on average, 1.75 few er children than their sisters who lived in the same parish as their mother. "Women in those days had a lot of kids, on average almost eight," says Engelhardt. But times were tough, and about half of a woman's offspring died before age 15. Such harsh conditions led to a range of reproductive success; the number of grandkids per grandmother in this database ranged from one to 195.

Why was being close to Grandma important?

Being geographically close to grandma curbed child mortality too and allowed mothers to start having kids at a younger age.

How much does having a grandmother help a toddler?

Having a grandmother age 50 to 75 increased a toddler's chance of surviving from age 2 to 5 by 30 percent. But the researchers found that the benefits of having a grandmother petered out after she passed age 75. In fact, the presence of an older paternal grandmother reduced a newborn's probability of surviving to age 2 by 37 percent.

How was knowledge transmitted?

For most of human history, this kind of knowledge was transmitted orally. "In North American indigenous communities, you see the transmission of agricultural knowledge across generations," she says. "In many cases from grandmother to grandchild."

When did women become grandmothers?

The study shows that the opportunity for grandmas to help was not constant over the years. On average, a woman became a grandmother in her 40s, and the number of grandkids she cared for steadily rose, peaking in her early 60s and then diminishing into her mid-70s.

Overview

Background

The grandmother effect

Criticisms and alternative hypotheses

See also