<p>I wonder, if the following model of the working and function of hypothetical <a href="https://en.wikipedia.org/wiki/Grandmother_cell" rel="nofollow noreferrer">grandmother</a> <a href="https://en.wikipedia.org/wiki/Alternative_explanations_of_the_%22grandmother%22_cell" rel="nofollow noreferrer">cells</a> is worthy of consideration or not (or if it is even a common view, just differently stated).</p>

<p>I assume that a rich inner presentation of my grandmother includes simultaneously imagining parts of her look, her voice, her smell, characteristics of her speech, behaviour and personality, her name. All this represented somehow by distributed neuron assemblies spread over the cortex, in modality specific areas (modality in a wide sense).</p>

<p>Each such assembly is somehow capable of activating other grandmother related assemblies, so if I read only the name of my grandmother (or e.g. a description of something she did in her characteristic way, or have a glance at a letter hand-written by her) a more or less rich inner representation of her arises.</p>

<p>This could happen in two quite different ways: those different modality specific assemblies activate each other in intricate ways <em>directly</em>, or they all activate a central small assembly (the grandmother assembly) which in turn activates the others. This assembly would work as (and have the function of) a hub. Its function would be both that of spreading and of integration of information. It would be used both for <em>creating</em> the global representation and for maintaining/stabilizing it.</p>

<p>For this hub to work, it must consist of different neurons, at least one for each modality - otherwise it would respond to rather arbitrary global patterns (summing up all excitatory inputs at once). But given that, it might work.</p>

<p>The truth (in the brain) will probably lie inbetween these two extremes: "no hub at all" and "very small hubs". And the hubs can be more or less important (because there are neuronal pathways bypassing them). And the hubs can be more or less specific (with respect to the cognitive item they are responsible for).</p>

<p>Is there a majority opinion among cognitive neuroscientists concerning these questions (existence/number and size of such hubs and their specificity and importance)?</p>

CC BY-SA 3.0
2017-09-04T15:16:52.370Z
With regard to the hub structure of the brain networks, it seems that there is a high number of hubs with low degree and a low number of hubs with a high degree. The brain also seems to be a small-world network.
holistic
CC BY-SA 3.0
2017-09-04T15:18:31.467Z
What kind of degree do you mean?
Hans-Peter Stricker
CC BY-SA 3.0
2017-09-04T15:46:03.037Z
degree in the graph theoretical sense of number of connections: https://en.wikipedia.org/wiki/Degree_(graph_theory)
holistic
CC BY-SA 3.0
2017-09-04T15:54:28.170Z
This means: a hub considered as a node connected with (many or few) other neuron assemblies considered as nodes?  Opposed to small hubs considered as small complete graphs (with low inner degree) compared to large complete graphs (with high inner degree)?
Hans-Peter Stricker
CC BY-SA 3.0
2017-09-04T15:58:23.913Z
I guess one should distinguish between inner and outer degree (of connectedness) of neuron assemblies. Both are important in their own right.
Hans-Peter Stricker
CC BY-SA 3.0
2017-09-04T16:41:31.207Z
Yes, a node is considered as a hub in this case. It is also possible to define a graph or more specifically a subset of nodes of a graph as being connected to another subset of a graph. This is then normally referred to as a clique or community which are connected with each other. And yes, it is important to distinguish between inner and outer degree in case it is measurable. Sometimes connectedness is defined as the inverse of the correlation coefficient of the measured signal time course (e.g. in fMRI) which is by definition symmetric and thus no direction of connectivity can be measured.
holistic
CC BY-SA 3.0
2017-09-05T06:01:24.767Z
Why inverse? Doesn't strong correlation indicate strong connectedness?
Hans-Peter Stricker
CC BY-SA 3.0
2017-09-05T09:44:24.800Z
Ah yes of course! That wasn't precisely enough formulated: I meant connectedness in the sense of distance, that is, distance=1/r -> the higher the correlation coefficient the smaller the distance, the closer the nodes.
holistic
CC BY-SA 3.0
2017-09-05T17:04:51.717Z
Are you asking how concepts/knowledge are represented in the brain? Does this question help answer your question? https://cogsci.stackexchange.com/q/494/4397
Seanny123
CC BY-SA 3.0
2017-09-06T08:07:50.060Z
@Seanny: I assume that grandmother (or gnostic) cells (or assemblies) are only one possible way to represent concepts (in this case: individuals) in the brain. I am not asking for *all* conceivable or biologically plausible ways. Thanks for the hint anyway, interesting enough.
Hans-Peter Stricker
<cognitive-neuroscience><theoretical-neuroscience><neuroanatomy><brain>
Hypothetical working and function of grandmother cells
Hans-Peter Stricker
# Hypothetical working and function of grandmother cells

(Asked by: username_0 on 2017-09-04)

I wonder, if the following model of the working and function of hypothetical [grandmother](https://en.wikipedia.org/wiki/Grandmother_cell) [cells](https://en.wikipedia.org/wiki/Alternative_explanations_of_the_%22grandmother%22_cell) is worthy of consideration or not (or if it is even a common view, just differently stated).

I assume that a rich inner presentation of my grandmother includes simultaneously imagining parts of her look, her voice, her smell, characteristics of her speech, behaviour and personality, her name. All this represented somehow by distributed neuron assemblies spread over the cortex, in modality specific areas (modality in a wide sense).

Each such assembly is somehow capable of activating other grandmother related assemblies, so if I read only the name of my grandmother (or e.g. a description of something she did in her characteristic way, or have a glance at a letter hand-written by her) a more or less rich inner representation of her arises.

This could happen in two quite different ways: those different modality specific assemblies activate each other in intricate ways *directly*, or they all activate a central small assembly (the grandmother assembly) which in turn activates the others. This assembly would work as (and have the function of) a hub. Its function would be both that of spreading and of integration of information. It would be used both for *creating* the global representation and for maintaining/stabilizing it.

For this hub to work, it must consist of different neurons, at least one for each modality - otherwise it would respond to rather arbitrary global patterns (summing up all excitatory inputs at once). But given that, it might work.

The truth (in the brain) will probably lie inbetween these two extremes: "no hub at all" and "very small hubs". And the hubs can be more or less important (because there are neuronal pathways bypassing them). And the hubs can be more or less specific (with respect to the cognitive item they are responsible for).

Is there a majority opinion among cognitive neuroscientists concerning these questions (existence/number and size of such hubs and their specificity and importance)?

**Tags:** cognitive-neuroscience, theoretical-neuroscience, neuroanatomy, brain

> **Comments:**
> **username_1**: With regard to the hub structure of the brain networks, it seems that there is a high number of hubs with low degree and a low number of hubs with a high degree. The brain also seems to be a small-world network.  
> **username_0**: What kind of degree do you mean?  
> **username_1**: degree in the graph theoretical sense of number of connections: https://en.wikipedia.org/wiki/Degree_(graph_theory)  
> **username_0**: This means: a hub considered as a node connected with (many or few) other neuron assemblies considered as nodes?  Opposed to small hubs considered as small complete graphs (with low inner degree) compared to large complete graphs (with high inner degree)?  
> **username_0**: I guess one should distinguish between inner and outer degree (of connectedness) of neuron assemblies. Both are important in their own right.  
> **username_1**: Yes, a node is considered as a hub in this case. It is also possible to define a graph or more specifically a subset of nodes of a graph as being connected to another subset of a graph. This is then normally referred to as a clique or community which are connected with each other. And yes, it is important to distinguish between inner and outer degree in case it is measurable. Sometimes connectedness is defined as the inverse of the correlation coefficient of the measured signal time course (e.g. in fMRI) which is by definition symmetric and thus no direction of connectivity can be measured.  
> **username_0**: Why inverse? Doesn't strong correlation indicate strong connectedness?  
> **username_1**: Ah yes of course! That wasn't precisely enough formulated: I meant connectedness in the sense of distance, that is, distance=1/r -> the higher the correlation coefficient the smaller the distance, the closer the nodes.  
> **username_2**: Are you asking how concepts/knowledge are represented in the brain? Does this question help answer your question? https://cogsci.stackexchange.com/q/494/4397  
> **username_0**: @Seanny: I assume that grandmother (or gnostic) cells (or assemblies) are only one possible way to represent concepts (in this case: individuals) in the brain. I am not asking for *all* conceivable or biologically plausible ways. Thanks for the hint anyway, interesting enough.  

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## 0 answers

